B Java Distilled

\(\newcommand{\footnotename}{footnote}\) \(\def \LWRfootnote {1}\) \(\newcommand {\footnote }[2][\LWRfootnote ]{{}^{\mathrm {#1}}}\) \(\newcommand {\footnotemark }[1][\LWRfootnote ]{{}^{\mathrm {#1}}}\) \(\let \LWRorighspace \hspace \) \(\renewcommand {\hspace }{\ifstar \LWRorighspace \LWRorighspace }\) \(\newcommand {\TextOrMath }[2]{#2}\) \(\newcommand {\mathnormal }[1]{{#1}}\) \(\newcommand \ensuremath [1]{#1}\) \(\newcommand {\LWRframebox }[2][]{\fbox {#2}} \newcommand {\framebox }[1][]{\LWRframebox } \) \(\newcommand {\setlength }[2]{}\) \(\newcommand {\addtolength }[2]{}\) \(\newcommand {\setcounter }[2]{}\) \(\newcommand {\addtocounter }[2]{}\) \(\newcommand {\arabic }[1]{}\) \(\newcommand {\number }[1]{}\) \(\newcommand {\noalign }[1]{\text {#1}\notag \\}\) \(\newcommand {\cline }[1]{}\) \(\newcommand {\directlua }[1]{\text {(directlua)}}\) \(\newcommand {\luatexdirectlua }[1]{\text {(directlua)}}\) \(\newcommand {\protect }{}\) \(\def \LWRabsorbnumber #1 {}\) \(\def \LWRabsorbquotenumber "#1 {}\) \(\newcommand {\LWRabsorboption }[1][]{}\) \(\newcommand {\LWRabsorbtwooptions }[1][]{\LWRabsorboption }\) \(\def \mathchar {\ifnextchar "\LWRabsorbquotenumber \LWRabsorbnumber }\) \(\def \mathcode #1={\mathchar }\) \(\let \delcode \mathcode \) \(\let \delimiter \mathchar \) \(\def \oe {\unicode {x0153}}\) \(\def \OE {\unicode {x0152}}\) \(\def \ae {\unicode {x00E6}}\) \(\def \AE {\unicode {x00C6}}\) \(\def \aa {\unicode {x00E5}}\) \(\def \AA {\unicode {x00C5}}\) \(\def \o {\unicode {x00F8}}\) \(\def \O {\unicode {x00D8}}\) \(\def \l {\unicode {x0142}}\) \(\def \L {\unicode {x0141}}\) \(\def \ss {\unicode {x00DF}}\) \(\def \SS {\unicode {x1E9E}}\) \(\def \dag {\unicode {x2020}}\) \(\def \ddag {\unicode {x2021}}\) \(\def \P {\unicode {x00B6}}\) \(\def \copyright {\unicode {x00A9}}\) \(\def \pounds {\unicode {x00A3}}\) \(\let \LWRref \ref \) \(\renewcommand {\ref }{\ifstar \LWRref \LWRref }\) \( \newcommand {\multicolumn }[3]{#3}\) \(\require {textcomp}\) \(\newcommand {\intertext }[1]{\text {#1}\notag \\}\) \(\let \Hat \hat \) \(\let \Check \check \) \(\let \Tilde \tilde \) \(\let \Acute \acute \) \(\let \Grave \grave \) \(\let \Dot \dot \) \(\let \Ddot \ddot \) \(\let \Breve \breve \) \(\let \Bar \bar \) \(\let \Vec \vec \) \(\renewcommand {\vec }{\boldsymbol }\) \(\newcommand {\Edge }{\ensuremath {\,\textemdash \,}}\) \(\newcommand \Const [1]{\text {\textsf {#1}}}\) \(\DeclareMathOperator {\lerp }{lerp}\) \(\DeclareMathOperator {\bitlen }{bitlen}\) \(\DeclareMathOperator {\sign }{sign}\) \(\newcommand {\I }{\mathrm {i}}\) \(\newcommand \AND {\mathbin {\&}}\) \(\newcommand \OR {\mathbin {|}}\) \(\newcommand \XOR {\mathbin {{}^{\wedge }}}\) \(\newcommand \shl {\ll }\) \(\newcommand \shr {\ggg }\) \(\newcommand \asr {\gg }\) \(\newcommand \NOT {\ensuremath {\mathord {\sim }}}\) \(\newcommand {\isep }{\mathrel {{.}\,{.}}}\) \(\newcommand {\Id }[1]{\mathit {#1}}\) \(\newcommand {\const }[1]{\mathsf {#1}}\) \(\newcommand {\algorithmname }[1]{\text {\textsc {#1}}}\) \(\newcommand {\bits }[1]{\text {#1}}\) \(\newcommand {\hexa }[1]{\mathtt {0x#1}}\) \(\newcommand {\num }[1]{#1}\) \(\newcommand {\qed }{\quad \square }\) \(\newcommand {\idiv }[2]{\lfloor #1/#2\rfloor }\) \(\newcommand \attribdot {\ensuremath {\mkern 1.5mu.\mkern 1.5mu}}\) \(\newcommand \attribxr [2]{#1\attribdot \text {#2}}\) \(\newcommand \attribir [2]{\Id {#1}\attribdot \text {#2}}\) \(\newcommand \attribii [2]{\Id {#1}\attribdot \Id {#2}}\) \(\newcommand \textsc [1]{#1}\) \(\require {colortbl}\) \(\let \LWRorigcolumncolor \columncolor \) \(\renewcommand {\columncolor }[2][named]{\LWRorigcolumncolor [#1]{#2}\LWRabsorbtwooptions }\) \(\let \LWRorigrowcolor \rowcolor \) \(\renewcommand {\rowcolor }[2][named]{\LWRorigrowcolor [#1]{#2}\LWRabsorbtwooptions }\) \(\let \LWRorigcellcolor \cellcolor \) \(\renewcommand {\cellcolor }[2][named]{\LWRorigcellcolor [#1]{#2}\LWRabsorbtwooptions }\) \(\newcommand {\tcbset }[1]{}\) \(\newcommand {\tcbsetforeverylayer }[1]{}\) \(\newcommand {\tcbox }[2][]{\boxed {\text {#2}}}\) \(\newcommand {\tcboxfit }[2][]{\boxed {#2}}\) \(\newcommand {\tcblower }{}\) \(\newcommand {\tcbline }{}\) \(\newcommand {\tcbtitle }{}\) \(\newcommand {\tcbsubtitle [2][]{\mathrm {#2}}}\) \(\newcommand {\tcboxmath }[2][]{\boxed {#2}}\) \(\newcommand {\tcbhighmath }[2][]{\boxed {#2}}\) \(\newcommand {\toprule }[1][]{\hline }\) \(\let \midrule \toprule \) \(\let \bottomrule \toprule \) \(\def \LWRbooktabscmidruleparen (#1)#2{}\) \(\newcommand {\LWRbooktabscmidrulenoparen }[1]{}\) \(\newcommand {\cmidrule }[1][]{\ifnextchar (\LWRbooktabscmidruleparen \LWRbooktabscmidrulenoparen }\) \(\newcommand {\morecmidrules }{}\) \(\newcommand {\specialrule }[3]{\hline }\) \(\newcommand {\addlinespace }[1][]{}\) \(\newcommand {\LWRsubmultirow }[2][]{#2}\) \(\newcommand {\LWRmultirow }[2][]{\LWRsubmultirow }\) \(\newcommand {\multirow }[2][]{\LWRmultirow }\) \(\newcommand {\mrowcell }{}\) \(\newcommand {\mcolrowcell }{}\) \(\newcommand {\STneed }[1]{}\) \(\newcommand {\LWRldelimtwo }[1][]{\text {#1}~\LWRbigdelim }\) \(\newcommand {\LWRldelimone }[2][]{\LWRldelimtwo }\) \(\def \ldelim #1#2{\def \LWRbigdelim {#1}\LWRldelimone }\) \(\newcommand {\LWRrdelimtwo }[1][]{\LWRbigdelim ~\text {#1}}\) \(\newcommand {\LWRrdelimone }[2][]{\LWRrdelimtwo }\) \(\def \rdelim #1#2{\def \LWRbigdelim {#1}\LWRrdelimone }\) \(\let \symnormal \mathit \) \(\let \symliteral \mathrm \) \(\let \symbb \mathbb \) \(\let \symbbit \mathbb \) \(\let \symcal \mathcal \) \(\let \symscr \mathscr \) \(\let \symfrak \mathfrak \) \(\let \symsfup \mathsf \) \(\let \symsfit \mathit \) \(\let \symbfsf \mathbf \) \(\let \symbfup \mathbf \) \(\newcommand {\symbfit }[1]{\boldsymbol {#1}}\) \(\let \symbfcal \mathcal \) \(\let \symbfscr \mathscr \) \(\let \symbffrak \mathfrak \) \(\let \symbfsfup \mathbf \) \(\newcommand {\symbfsfit }[1]{\boldsymbol {#1}}\) \(\let \symup \mathrm \) \(\let \symbf \mathbf \) \(\let \symit \mathit \) \(\let \symsf \symsfit \) \(\let \symtt \mathtt \) \(\let \symbffrac \mathbffrac \) \(\newcommand {\mathfence }[1]{\mathord {#1}}\) \(\newcommand {\mathover }[1]{#1}\) \(\newcommand {\mathunder }[1]{#1}\) \(\newcommand {\mathaccent }[1]{#1}\) \(\newcommand {\mathbotaccent }[1]{#1}\) \(\newcommand {\mathalpha }[1]{\mathord {#1}}\) \(\def\Alpha{\unicode{x1D6E2}}\) \(\def\Beta{\unicode{x1D6E3}}\) \(\def\Gamma{\unicode{x1D6E4}}\) \(\def\Digamma{\mathit{\unicode{x03DC}}}\) \(\def\Delta{\unicode{x1D6E5}}\) \(\def\Epsilon{\unicode{x1D6E6}}\) \(\def\Zeta{\unicode{x1D6E7}}\) \(\def\Eta{\unicode{x1D6E8}}\) \(\def\Theta{\unicode{x1D6E9}}\) \(\def\Vartheta{\unicode{x1D6F3}}\) \(\def\Iota{\unicode{x1D6EA}}\) \(\def\Kappa{\unicode{x1D6EB}}\) \(\def\Lambda{\unicode{x1D6EC}}\) \(\def\Mu{\unicode{x1D6ED}}\) \(\def\Nu{\unicode{x1D6EE}}\) \(\def\Xi{\unicode{x1D6EF}}\) \(\def\Omicron{\unicode{x1D6F0}}\) \(\def\Pi{\unicode{x1D6F1}}\) \(\def\Rho{\unicode{x1D6F2}}\) \(\def\Sigma{\unicode{x1D6F4}}\) \(\def\Tau{\unicode{x1D6F5}}\) \(\def\Upsilon{\unicode{x1D6F6}}\) \(\def\Phi{\unicode{x1D6F7}}\) \(\def\Chi{\unicode{x1D6F8}}\) \(\def\Psi{\unicode{x1D6F9}}\) \(\def\Omega{\unicode{x1D6FA}}\) \(\def\alpha{\unicode{x1D6FC}}\) \(\def\beta{\unicode{x1D6FD}}\) \(\def\varbeta{\unicode{x03D0}}\) \(\def\gamma{\unicode{x1D6FE}}\) \(\def\digamma{\mathit{\unicode{x03DD}}}\) \(\def\delta{\unicode{x1D6FF}}\) \(\def\epsilon{\unicode{x1D716}}\) \(\def\varepsilon{\unicode{x1D700}}\) \(\def\zeta{\unicode{x1D701}}\) \(\def\eta{\unicode{x1D702}}\) \(\def\theta{\unicode{x1D703}}\) \(\def\vartheta{\unicode{x1D717}}\) \(\def\iota{\unicode{x1D704}}\) \(\def\kappa{\unicode{x1D705}}\) \(\def\varkappa{\unicode{x1D718}}\) \(\def\lambda{\unicode{x1D706}}\) \(\def\mu{\unicode{x1D707}}\) \(\def\nu{\unicode{x1D708}}\) \(\def\xi{\unicode{x1D709}}\) \(\def\omicron{\unicode{x1D70A}}\) \(\def\pi{\unicode{x1D70B}}\) \(\def\varpi{\unicode{x1D71B}}\) \(\def\rho{\unicode{x1D70C}}\) \(\def\varrho{\unicode{x1D71A}}\) \(\def\sigma{\unicode{x1D70E}}\) \(\def\varsigma{\unicode{x1D70D}}\) \(\def\tau{\unicode{x1D70F}}\) \(\def\upsilon{\unicode{x1D710}}\) \(\def\phi{\unicode{x1D719}}\) \(\def\varphi{\unicode{x1D711}}\) \(\def\chi{\unicode{x1D712}}\) \(\def\psi{\unicode{x1D713}}\) \(\def\omega{\unicode{x1D714}}\) \(\def\upAlpha{\unicode{x0391}}\) \(\def\upBeta{\unicode{x0392}}\) \(\def\upGamma{\unicode{x0393}}\) \(\def\upDigamma{\unicode{x03DC}}\) \(\def\upDelta{\unicode{x0394}}\) \(\def\upEpsilon{\unicode{x0395}}\) \(\def\upZeta{\unicode{x0396}}\) \(\def\upEta{\unicode{x0397}}\) \(\def\upTheta{\unicode{x0398}}\) \(\def\upVartheta{\unicode{x03F4}}\) \(\def\upIota{\unicode{x0399}}\) \(\def\upKappa{\unicode{x039A}}\) \(\def\upLambda{\unicode{x039B}}\) \(\def\upMu{\unicode{x039C}}\) \(\def\upNu{\unicode{x039D}}\) \(\def\upXi{\unicode{x039E}}\) \(\def\upOmicron{\unicode{x039F}}\) \(\def\upPi{\unicode{x03A0}}\) \(\def\upVarpi{\unicode{x03D6}}\) \(\def\upRho{\unicode{x03A1}}\) \(\def\upSigma{\unicode{x03A3}}\) \(\def\upTau{\unicode{x03A4}}\) \(\def\upUpsilon{\unicode{x03A5}}\) \(\def\upPhi{\unicode{x03A6}}\) \(\def\upChi{\unicode{x03A7}}\) \(\def\upPsi{\unicode{x03A8}}\) \(\def\upOmega{\unicode{x03A9}}\) \(\def\itAlpha{\unicode{x1D6E2}}\) \(\def\itBeta{\unicode{x1D6E3}}\) \(\def\itGamma{\unicode{x1D6E4}}\) \(\def\itDigamma{\mathit{\unicode{x03DC}}}\) \(\def\itDelta{\unicode{x1D6E5}}\) \(\def\itEpsilon{\unicode{x1D6E6}}\) \(\def\itZeta{\unicode{x1D6E7}}\) \(\def\itEta{\unicode{x1D6E8}}\) \(\def\itTheta{\unicode{x1D6E9}}\) \(\def\itVartheta{\unicode{x1D6F3}}\) \(\def\itIota{\unicode{x1D6EA}}\) \(\def\itKappa{\unicode{x1D6EB}}\) \(\def\itLambda{\unicode{x1D6EC}}\) \(\def\itMu{\unicode{x1D6ED}}\) \(\def\itNu{\unicode{x1D6EE}}\) \(\def\itXi{\unicode{x1D6EF}}\) \(\def\itOmicron{\unicode{x1D6F0}}\) \(\def\itPi{\unicode{x1D6F1}}\) \(\def\itRho{\unicode{x1D6F2}}\) \(\def\itSigma{\unicode{x1D6F4}}\) \(\def\itTau{\unicode{x1D6F5}}\) \(\def\itUpsilon{\unicode{x1D6F6}}\) \(\def\itPhi{\unicode{x1D6F7}}\) \(\def\itChi{\unicode{x1D6F8}}\) \(\def\itPsi{\unicode{x1D6F9}}\) \(\def\itOmega{\unicode{x1D6FA}}\) \(\def\upalpha{\unicode{x03B1}}\) \(\def\upbeta{\unicode{x03B2}}\) \(\def\upvarbeta{\unicode{x03D0}}\) \(\def\upgamma{\unicode{x03B3}}\) \(\def\updigamma{\unicode{x03DD}}\) \(\def\updelta{\unicode{x03B4}}\) \(\def\upepsilon{\unicode{x03F5}}\) \(\def\upvarepsilon{\unicode{x03B5}}\) \(\def\upzeta{\unicode{x03B6}}\) \(\def\upeta{\unicode{x03B7}}\) \(\def\uptheta{\unicode{x03B8}}\) \(\def\upvartheta{\unicode{x03D1}}\) \(\def\upiota{\unicode{x03B9}}\) \(\def\upkappa{\unicode{x03BA}}\) \(\def\upvarkappa{\unicode{x03F0}}\) \(\def\uplambda{\unicode{x03BB}}\) \(\def\upmu{\unicode{x03BC}}\) \(\def\upnu{\unicode{x03BD}}\) \(\def\upxi{\unicode{x03BE}}\) \(\def\upomicron{\unicode{x03BF}}\) \(\def\uppi{\unicode{x03C0}}\) \(\def\upvarpi{\unicode{x03D6}}\) \(\def\uprho{\unicode{x03C1}}\) \(\def\upvarrho{\unicode{x03F1}}\) \(\def\upsigma{\unicode{x03C3}}\) \(\def\upvarsigma{\unicode{x03C2}}\) \(\def\uptau{\unicode{x03C4}}\) \(\def\upupsilon{\unicode{x03C5}}\) \(\def\upphi{\unicode{x03D5}}\) \(\def\upvarphi{\unicode{x03C6}}\) \(\def\upchi{\unicode{x03C7}}\) \(\def\uppsi{\unicode{x03C8}}\) \(\def\upomega{\unicode{x03C9}}\) \(\def\italpha{\unicode{x1D6FC}}\) \(\def\itbeta{\unicode{x1D6FD}}\) \(\def\itvarbeta{\unicode{x03D0}}\) \(\def\itgamma{\unicode{x1D6FE}}\) \(\def\itdigamma{\mathit{\unicode{x03DD}}}\) \(\def\itdelta{\unicode{x1D6FF}}\) \(\def\itepsilon{\unicode{x1D716}}\) \(\def\itvarepsilon{\unicode{x1D700}}\) \(\def\itzeta{\unicode{x1D701}}\) \(\def\iteta{\unicode{x1D702}}\) \(\def\ittheta{\unicode{x1D703}}\) \(\def\itvartheta{\unicode{x1D717}}\) \(\def\itiota{\unicode{x1D704}}\) \(\def\itkappa{\unicode{x1D705}}\) \(\def\itvarkappa{\unicode{x1D718}}\) \(\def\itlambda{\unicode{x1D706}}\) \(\def\itmu{\unicode{x1D707}}\) \(\def\itnu{\unicode{x1D708}}\) \(\def\itxi{\unicode{x1D709}}\) \(\def\itomicron{\unicode{x1D70A}}\) \(\def\itpi{\unicode{x1D70B}}\) \(\def\itvarpi{\unicode{x1D71B}}\) \(\def\itrho{\unicode{x1D70C}}\) \(\def\itvarrho{\unicode{x1D71A}}\) \(\def\itsigma{\unicode{x1D70E}}\) \(\def\itvarsigma{\unicode{x1D70D}}\) \(\def\ittau{\unicode{x1D70F}}\) \(\def\itupsilon{\unicode{x1D710}}\) \(\def\itphi{\unicode{x1D719}}\) \(\def\itvarphi{\unicode{x1D711}}\) \(\def\itchi{\unicode{x1D712}}\) \(\def\itpsi{\unicode{x1D713}}\) \(\def\itomega{\unicode{x1D714}}\) \(\let \lparen (\) \(\let \rparen )\) \(\newcommand {\cuberoot }[1]{\,{}^3\!\!\sqrt {#1}}\,\) \(\newcommand {\fourthroot }[1]{\,{}^4\!\!\sqrt {#1}}\,\) \(\newcommand {\longdivision }[1]{\mathord {\unicode {x027CC}#1}}\) \(\newcommand {\mathcomma }{,}\) \(\newcommand {\mathcolon }{:}\) \(\newcommand {\mathsemicolon }{;}\) \(\newcommand {\overbracket }[1]{\mathinner {\overline {\ulcorner {#1}\urcorner }}}\) \(\newcommand {\underbracket }[1]{\mathinner {\underline {\llcorner {#1}\lrcorner }}}\) \(\newcommand {\overbar }[1]{\mathord {#1\unicode {x00305}}}\) \(\newcommand {\ovhook }[1]{\mathord {#1\unicode {x00309}}}\) \(\newcommand {\ocirc }[1]{\mathord {#1\unicode {x0030A}}}\) \(\newcommand {\candra }[1]{\mathord {#1\unicode {x00310}}}\) \(\newcommand {\oturnedcomma }[1]{\mathord {#1\unicode {x00312}}}\) \(\newcommand {\ocommatopright }[1]{\mathord {#1\unicode {x00315}}}\) \(\newcommand {\droang }[1]{\mathord {#1\unicode {x0031A}}}\) \(\newcommand {\leftharpoonaccent }[1]{\mathord {#1\unicode {x020D0}}}\) \(\newcommand {\rightharpoonaccent }[1]{\mathord {#1\unicode {x020D1}}}\) \(\newcommand {\vertoverlay }[1]{\mathord {#1\unicode {x020D2}}}\) \(\newcommand {\leftarrowaccent }[1]{\mathord {#1\unicode {x020D0}}}\) \(\newcommand {\annuity }[1]{\mathord {#1\unicode {x020E7}}}\) \(\newcommand {\widebridgeabove }[1]{\mathord {#1\unicode {x020E9}}}\) \(\newcommand {\asteraccent }[1]{\mathord {#1\unicode {x020F0}}}\) \(\newcommand {\threeunderdot }[1]{\mathord {#1\unicode {x020E8}}}\) \(\newcommand {\Bbbsum }{\mathop {\unicode {x2140}}\limits }\) \(\newcommand {\oiint }{\mathop {\unicode {x222F}}\limits }\) \(\newcommand {\oiiint }{\mathop {\unicode {x2230}}\limits }\) \(\newcommand {\intclockwise }{\mathop {\unicode {x2231}}\limits }\) \(\newcommand {\ointclockwise }{\mathop {\unicode {x2232}}\limits }\) \(\newcommand {\ointctrclockwise }{\mathop {\unicode {x2233}}\limits }\) \(\newcommand {\varointclockwise }{\mathop {\unicode {x2232}}\limits }\) \(\newcommand {\leftouterjoin }{\mathop {\unicode {x27D5}}\limits }\) \(\newcommand {\rightouterjoin }{\mathop {\unicode {x27D6}}\limits }\) \(\newcommand {\fullouterjoin }{\mathop {\unicode {x27D7}}\limits }\) \(\newcommand {\bigbot }{\mathop {\unicode {x27D8}}\limits }\) \(\newcommand {\bigtop }{\mathop {\unicode {x27D9}}\limits }\) \(\newcommand {\xsol }{\mathop {\unicode {x29F8}}\limits }\) \(\newcommand {\xbsol }{\mathop {\unicode {x29F9}}\limits }\) \(\newcommand {\bigcupdot }{\mathop {\unicode {x2A03}}\limits }\) \(\newcommand {\bigsqcap }{\mathop {\unicode {x2A05}}\limits }\) \(\newcommand {\conjquant }{\mathop {\unicode {x2A07}}\limits }\) \(\newcommand {\disjquant }{\mathop {\unicode {x2A08}}\limits }\) \(\newcommand {\bigtimes }{\mathop {\unicode {x2A09}}\limits }\) \(\newcommand {\modtwosum }{\mathop {\unicode {x2A0A}}\limits }\) \(\newcommand {\sumint }{\mathop {\unicode {x2A0B}}\limits }\) \(\newcommand {\intbar }{\mathop {\unicode {x2A0D}}\limits }\) \(\newcommand {\intBar }{\mathop {\unicode {x2A0E}}\limits }\) \(\newcommand {\fint }{\mathop {\unicode {x2A0F}}\limits }\) \(\newcommand {\cirfnint }{\mathop {\unicode {x2A10}}\limits }\) \(\newcommand {\awint }{\mathop {\unicode {x2A11}}\limits }\) \(\newcommand {\rppolint }{\mathop {\unicode {x2A12}}\limits }\) \(\newcommand {\scpolint }{\mathop {\unicode {x2A13}}\limits }\) \(\newcommand {\npolint }{\mathop {\unicode {x2A14}}\limits }\) \(\newcommand {\pointint }{\mathop {\unicode {x2A15}}\limits }\) \(\newcommand {\sqint }{\mathop {\unicode {x2A16}}\limits }\) \(\newcommand {\intlarhk }{\mathop {\unicode {x2A17}}\limits }\) \(\newcommand {\intx }{\mathop {\unicode {x2A18}}\limits }\) \(\newcommand {\intcap }{\mathop {\unicode {x2A19}}\limits }\) \(\newcommand {\intcup }{\mathop {\unicode {x2A1A}}\limits }\) \(\newcommand {\upint }{\mathop {\unicode {x2A1B}}\limits }\) \(\newcommand {\lowint }{\mathop {\unicode {x2A1C}}\limits }\) \(\newcommand {\bigtriangleleft }{\mathop {\unicode {x2A1E}}\limits }\) \(\newcommand {\zcmp }{\mathop {\unicode {x2A1F}}\limits }\) \(\newcommand {\zpipe }{\mathop {\unicode {x2A20}}\limits }\) \(\newcommand {\zproject }{\mathop {\unicode {x2A21}}\limits }\) \(\newcommand {\biginterleave }{\mathop {\unicode {x2AFC}}\limits }\) \(\newcommand {\bigtalloblong }{\mathop {\unicode {x2AFF}}\limits }\) \(\newcommand {\arabicmaj }{\mathop {\unicode {x1EEF0}}\limits }\) \(\newcommand {\arabichad }{\mathop {\unicode {x1EEF1}}\limits }\)

B.2 Primitive Types

In Java, basic data types such as int or float are referred to as primitive types. These types are built into the language itself and cannot be modified or extended by the programmer, but they can be used to declare variables, return types, and the types of function arguments, and the usual arithmetic, comparison, and logical operators are available to operate on them. The full list of primitive types and the available operators is shown in Table B.1.

Table B.1 Primitive types in Java
.
Type Literal Bits Operators

Wrapper

byte 8 conversion to int

Byte

short 16 conversion to int

Short

char 'a', 'Ñ' 16 conversion to int

Character

int 0x7f, -4096 32 + - * / %

Integer

~ ^ & | << >> >>>
long 0x7fL, -4096L 64 + - * / %

Long

~ ^ & | << >> >>>
float -1.6f, 2e-5f 32 + - * /

Float

double -1.6, 2e-5 64 + - * /

Double

boolean true, false ! && ||

Boolean

void

Void

It is possible to convert between the numeric types listed in the upper two parts of the table. In cases where there can be no loss of data, these conversions are performed automatically; this is known as type promotion:

byte b = 17;
int c = b;            // byte promoted to int 
long l = 12 + 17L;    // 12 promoted to long
double d = 12 * 1.0f; // 12 promoted to float, then to double

In cases where data loss is possible, the conversion must be performed manually using type casts:

int i = (int)(12 + 17L);      // conversion from long to int
float f = (float)(12 * 1.0);  // conversion from double to float
int j = (int)f;               // conversion from float to int

Type conversion isn’t available for the boolean type. Instead, we have to use if statements or the ternary operator ?: to convert Boolean values to numbers and comparison operators such as != to convert numbers to Booleans:

int v = (c > b) ? 1 : 0;  // explicit conversion from boolean to int
boolean b = (v != 0);     // explicit conversion from int to boolean

Another peculiarity of Java worth noting is the relationship between primitive types and the wrapper classes indicated in the last column of Table B.1. As you can see, there is one wrapper class for every type. These classes serve two purposes. First, as mentioned in the previous section, each wrapper class contains a selection of useful static methods and constants for working with the corresponding primitive types. For instance, Float defines methods for hashing, comparing, and inspecting floating point numbers, for converting to and from decimal strings, and useful constants such as POSITIVE_INFINITY and MAX_VALUE.

The second purpose of these wrapper classes is to actually wrap values of the corresponding primitive types. As an example, the following listing demonstrates how to use the valueOf() method to create an instance of Integer that holds the number 13 and later retrieve this value using the intValue() method:

Integer i = Integer.valueOf(13);
int j = i.intValue();
assert j == 13;

Similar methods exist for the other wrapper classes. The process of wrapping a primitive value in its wrapper class is also referred to as boxing and retrieving the value as unboxing of primitive data types. Boxing and unboxing are so common in Java that they are often performed automatically. The previous example, for instance, can also be written as

Integer i = 13;  // automatic boxing
int j = i;       // automatic unboxing

Because all wrapper classes derive from Object, it is possible define variables that hold either an integer or a floating point number (or, in fact, any other object):

Object anything;
if (Math.random() < 0.5) {
    anything = 42;
} else {
    anything = 3.14159f;
}
if (anything instanceof Integer i) {
    System.out.println("It's an integer: " + i);
} else if (anything instanceof Float f) {
    System.out.println("It's a float: " + f);
}

In the early days of Java, this technique was used to implement data structures that can hold all kinds of values, including primitive types. Today, such data structures are usually implemented using generics, which we will discuss in more detail in Appendix B.5. For historical reasons, generics don’t work with primitive types such as int or float but only with types derived from Object1. If you want to create an ArrayList of integers, for example, you have to use the wrapper type Integer instead of int:

// var list = new ArrayList<int>();  // !! compile-time error
var list = new ArrayList<Integer>(); // OK
list.add(1);         // box 1 by converting it to Integer
int x = list.get(0); // unbox result by converting it to int

1 This includes all types defined using class, interface, record, and enum.