OPI_LR2011_ch3

11

= 1.2 – ; Java

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boolean @

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boolean b = true, bb = false, bool2;

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((n != 0) &&(m/n > 0.001) (n == 0) ||(m/n > 0.001)

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–(complement) ~( );

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f, g f , i g f .

1.2.4 , , 4 4

E Java : float double. ' :

float S = 0.001, y = -34.789; double 21 = -16.2305, z2;

1.2.5 ( ;,< 4 " E" )

' @ (simple assignment operator)

f =, ,

(, :

S = 3.5, y = 2 *(S - 0.567) /(S + 2), b = S < y, bb = S >= y && b.

C @ f i 11

@ (compound assignment operators):

+=, -=, *=, /=, %=, &=, |=, ^=, <<=, >>= ; >>>=.

1.2.6 ( 4

: Java @ f:

– g 'f;

15

int result = 0; if(testval > target)

result = +1;

else if(testval < target) result = -1;

else

result = 0; // a<8\=b:;95 return result;

}

public static void main(String[] args) { System.out.println(test(10, 5)); System.out.println(test(5, 10)); System.out.println(test(5, 5));

}

}

( continue , !, 14

. continue f . ? f +. ' g + f continue

@f .

+ continue f :

for(int i = 0; i < N; i++){ if(i == j) continue;

s += 1.0 /(i - j); }

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continue R8:P=

f, +, Java, +

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@. ;

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( break !, 1

f ,

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Ml: { // a2@78f78> <g2P

h2: { // iPg=6O7/> <g2P - 64N\/> 48@O7; h3: { // .4O:8> 48@O7; @Pg=6O729:8...

if(j29; :4=0/g295) break M2;

//lPj2 true, :O :N: 78]2\2 7O @/P27Nb:;95

}

//.N: :O^ 78]2\2 7O @/P27Nb:;95

}

// mn6/ 0O4O6=b:;95 PO4N@=775

}

16

Break Continue

- ( (

@ , @ break continue. Break f , i

g, . Continue f

f , @ @.

D f break continue

for while:

// ?OR279:4Nb break > continue. public class BreakAndContinue {

public static void main(String[] args) { for(int i = 0; i < 100; i++) {

if(i == 74) break; // @/S86 83 _/PgN for if(i % 9 != 0) continue; // q=9:N07= 8:O4=_85 System.out.println(i);

}

int i = 0;

// "qO9P87]O77/> _/Pg": while(true) {

i++;

int j = i * 27;

if(j == 1269) break; // i/S86 83 _/PgN

if(i % 10 != 0) continue; // s 02]=:2P _/PgN System.out.println(i);

} } }

for i 100, i

break , i @

74. 0 continue f (

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0

9

18

27

36

45

54

63

72

10

17

20

30

40

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Return

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f (i f f ,

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test( ), i, (

:

public class IfElse2 {

static int test(int testval, int target) { int result = 0;

if(testval > target) return +1;

else if(testval < target) return -1;

else

return 0; // a<8\=b:;95

}

public static void main(String[] args) { System.out.println(test(10, 5)); System.out.println(test(5, 10)); System.out.println(test(5, 5));

}

}

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return.

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f .

switch(t){

case P279:@/41: 20O4=:241 case P279:@/42: 20O4=:242 case P279:@/4: 20O4=:24 default: 20O4=:24Def

}

18

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long. D (, ,

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g, .

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While

7 while :

while([2\8]7O @/4=^O775) 879:4NP_85

e @f ,

i ( @ @ f@ .

; , i f ,

:

// ?OR279:4=_85 _/PgN while. public class WhileTest {

public static void main(String[] args) { double r = 0;

while(r < 0.99d) { r = Math.random();

System.out.println(r);

}

}

}

; f random( )

Math, i f double ( 0 1 (0 @, 1 @). ' while , “(

, 0.99 g”. ‘, f , (

(.

19

Do-while

7 do-while :

do

879:4NP_85 while([2\8]7O @/4=^O775);

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do-while ( f g ,

i f .

while, i f @ g ,

f. : do-while f g, ( while.

For

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f , i @

for. 7 for :

for(878_8=g83=_85; g2\8]7/> @/4=^3; P42P) 879:4NP_85

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false, ( , i f@ for. : ( f

.

D for f “ ”:

//?OR279:4=_85 _/PgN "for" 6g5 9Pg=6=775

//90/9PN @98S ASCII 9/R@2g8@.

public class ListCharacters {

public static void main(String[] args) { for( char c = 0; c < 128; c++)

if (c != 26 ) // ANSI x]/jO775 OP4=7= System.out.println(

"value: " + (int)c + " character: " + c);

}

}

? ( for,

:

for(int i = 0, j = 1; i < 10 && j != 11; i++, j++)

/* :8g2 _/PgN for */;

? int for @ ( f i j.

@ f (

for. ? ( g

.

20

1.2.7 4"4

4"4

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Java . .

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f (reference) , i

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double[] =, b;

E – (installation). :

f – (, f

' , ( f

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f@ new , i f '

'f f

f . :,

= = new double[5]; b = new double[100]; ar = new int[50];

; – (initialization). :

( @ . :,

=[0] = 0.01; =[1] = -3.4; =[2] = 2:.89; =[3] = 4.5; =[4] = -6.7; for(int i = 0; i < 100; i++) b[i] = 1.0 /i;

for(int i = 0; i < 50; i++) ar[i] = 2 * i + 1;

. ( : a [a.length - 1],

— a [a.length - 2] . . ”

@ :

double aMin = a[0], aMax = aMin; for(int i = 1; i < a.length; i++){ if <a[i] < aMin) aMin = a[i]; if(a[i] > aMax) aMax = a[i];

}

double range = aMax - aMin;