Java 流程控制

Java if-else switch-casefor-loopfor/infor-eachwhile-loopdo-while-loop

Java Java C (decision making) (Loop) (Exception) (Special Loop)

Java (decision making)if-elseswitch-case

Java (Loop) for-loopfor-infor-eachwhile-loopdo-while-loop

Java (Exception)try-catch-finallythrow

Java (Special Loop)labelbreakcontinue

if-elseif-else if-else if(A > B)A B ?

if-elseif else if-else true if (program statement or block) false else

if-elseif else 1if if truefalse

if-elseif else 2if if truefalse(else )else

if-elseif else 3

if-elseif else

123456if( boolean-expression) { // if }else { //else }

if-elseif else 100

1234567int money = 100;if(money == 100) { System.out.println( 100);}else { System.out.println( 100);}

if-elseif else 100

1234567int money = 200;if(money == 100) { System.out.println( 100);}else { System.out.println( 100);}

if-elseif else

1234567int money = 100;if(money = 100) { System.out.println( 100);}else { System.out.println( 100);}

if-elseif else if(money == 100) { ... }== if(money = 100) { ... }= if-else if()

if-elseif else true

1234567boolean b = true;if(b) { System.out.println(true);}else { System.out.println(false);}

if-elseif else true

1234567boolean b = true;if(b == true) { System.out.println(true);}else { System.out.println(false);}

if-elseif else ()false

1234567boolean b = true;if(b = false) { System.out.println(true);}else { System.out.println(false);}

if-elseif else boolean b = true; if(b = false) {...}boolean b

if-elseif else

123456if( boolean-expression) // if else //else ...//

if-elseif else

1234if(boolean-exp) // if else //else ...//

if-elseif else

1234567int a = 1;if(a > 0) System.out.println(A); System.out.println(B); else System.out.println(C);System.out.println(D);

if-elseif else

1234567if(boolean-exp) // if else if(boolean-exp) // else if else // else //

if-elseif else A, C

123456boolean b = true;if(b = true)System.out.println(A);elseSystem.out.println(B);System.out.println(C);

switch-caseswitch-case if-else selectorcharbyteshortintcasebreak switch-case int

switch-caseswitch-case switch(x)case 1case 2......breaktruedefault...x

switch-caseswitch-case switch(x)case 1case 2......falsedefault...truebreak

switch-caseswitch-case switch(x)case 1case 2......default...

switch-caseswitch-case switch(x)case 1case 2......default...break

switch-caseswitch-case switch(x)case 1case 2......default...

switch-caseswitch-case A

12345678int x = 1;switch(x) { case 1: System.out.print(A); break; case 2: System.out.print(B);}

switch-caseswitch-case AB

1234567int x = 1;switch(x) { case 1: System.out.print(A); case 2: System.out.print(B);}


12345678char x = A;switch(x) { case A: System.out.print(A); break; case B: System.out.print(B);}

switch-caseswitch-case AASCII(65) = A

12345678char x = A;switch(x) { case 65: System.out.print(A); break; case 66: System.out.print(B);}

switch-caseASCII table

10 16 8 Char000null... 6541101A6642102B... 9761141a

switch-caseswitch-case

123456789char x = A;char valueA = A;switch(x) { case valueA: System.out.print(A); break; case B: System.out.print(B);}


123456789char x = A;final char valueA = A;switch(x) { case valueA: System.out.print(A); break; case B: System.out.print(B);}

switch-case switch(x)x bytecharshort int int bytecharshort int switch-case x int int long double int int

switch-caseswitch(expression)(argument)

switch(x) OKswitch(x, y) Error

switch-casedefault switch-case

switch(x) { default: ... }

switch-case switch-case case default switch-case (does nothing)int i = 100; switch(i) { case 200: System.out.println(A); }Nothing !

switch-case switch-case case (must be unique) case

switch(x) { case A: case A: }

switch-casedefaut switch-case

switch(x) { case A: default: default: }

for-loopfor-loopwhiledo-while for-each (iteration loop) false

for-loopfor-loop (step by step) 3 initializationboolean-expressionstepping

for-loopinitializationfor-loop for-loop

for-loopboolean-expression true for-loop false for-loop

for-loopsteppingstep

for-loopfor-loop for-loop initializationboolean-exprsteppingtruefalse

for-loopfor-loop 1, 2, 3, 4, 5, 6 ,7 ,8 ,9 ,10

123for(int i=1 ; i

for-loopfor-loop nested loop for-loop for-loop

123456for(int i=1 ; i

for-loopbreak continue for-loop break continue break continue

for-loopbreak continue1 2 4 5 7 stepping for-loop

123456789for(int i=1 ; i

for-looplabellabel Java label (label name)()

for-looplabel

1234MyLoop_1:for(int i=1 ; i

for-looplabel

1234567891011121314 OuterLoop // () for( ; ; ) { // InnerLoop for( ; ; ) { // break InnerLoop; // ... continue InnerLoop; // ... break OuterLoop; // ... continue OuterLoop; // ... } }

for-loopfor-loop Java () for-loop for-loop initialization stepping

for-loopinitialization ()

initialization int i=0, j =0 i j int

12()for(int i=0, j=0boolean-expstepping);


j initialization

12()for(int i=0, int j=0boolean-expstepping);


i j for-loop

1234()String j = null;int i =0;for(i=0, j=Java boolean-expstepping);

for-loopstepping ()

(stepping) i++ j++

123for(int i=0, j=0boolean-expressioni++, j++) { // statement}

for-loopfor-loop for() {...}for-loop 2 ()initialization stepping ()for-loop for(;;);

for/infor-eachfor/infor-each JavaSE 5.0for-each (array)(collection)for-each

for/infor-eachfor-each for-loop Java

for/infor-eachfor-each

for ( : )

for/infor-each for-loopString[] exams = {"SCJP", "SCWCD", "SCMAD"};for-loopSCJP, SCWCD, SCMAD,

123for(int i=0;i

for/infor-each - for-eachString[] exams = {"SCJP", "SCWCD", "SCMAD"};for-eachSCJP, SCWCD, SCMAD,

123for(String ex : exams) { System.out.print(ex + ", ");}

for/infor-each - for-eachSCJP, SCWCD, SCMAD, MCSD, MCAD, MCDBA,

12345678910String[][] exams = { {"SCJP", "SCWCD", "SCMAD"}, {"MCSD", "MCAD", "MCDBA"} };for(String[] ex : exams) { for(String e : ex) { System.out.print(e + ", "); }}System.out.println();

while-loopwhile-loop ture false

while-loopwhile-loop boolean truefalse

while-loopwhile-loop

123while(boolean-expression) { // statement}

while-loop while-loop Java,Java,Java,

12345int count = 3;while(count > 0) { System.out.print(Java,); --count;}

while-loopbreak continue while while loop

1234567 while(boolean-expression){ // statement break; // statement continue; // statement }

do-while-loopdo-while-loop while-loop while-loop while true while do-while-loop while while

do-while-loop do-while-loop while

do-while-loopdo-while-loop boolean truefalse

do-while-loopdo-while-loop

123do {// statement} while(boolean-expression)

do-while-loop do-while-loop Java, ;

1234int count = -1;do { System.out.print(Java,);} while(count > 0)

do-while-loopbreak continue while do-while-loop

12345678 do{ // statement break; // statement continue; // statement } while(boolean-expression);

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