Chap02

  • December 2019
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='&,B61='4"5H'.&,B66'"942(7/B 6/0-A@D/(E ='6'"&/6C,8"D/"7/ ='"@4' W##,-LEC/6"A-."E<#2@1K+W##,-LE %BG52G@29"D,@<:(/' A IH"='&,B6  amount = 121+14; .0%C,8"D/"7/='"@4'W##,-LERSB6.G52H':;" Pct <#2@1K+W##,-LE %BG52#69"D,@ <:(amount ='&,B61='4"5H'.D2/60%I7B/D,@<:(/$MH '652'"R2'$07/1'(9I2='&,B6IH"  1 = x; :;"1'(9I2='&,B6 %BG0H*M1D2/6 -('H'6 9%B 5FG0H&'0'(* .%B 1K+W##,-LE %BG52.'1 "A-."EH'C/6x G52 "/1.'1"%8('&'0'(* .%B "='I7B/D,@<:( %B.1='4"5H'0':(1/+9""A-."EG52 /' A IH"  x = x+1; :;"='&,B6 %B942"A-."E-AB0H'C/6D,@<:( x %B0%/$MH<#2@G:/%1P<#2@"='W##,-LE %BG521K+ G@29"D,@<:(xIH"5A0/' A IH"*2'x 0%H':;"t.1#'$:;"… ('&'0'(* %B.:(1')<#1='4"5H'(AB0D2"C/6D,@<:( >'$9"='&,B65%$@1,"G52 !5$0%(:M <++='&,6B 5,6"%8 [modifier] dataType variableName = expression [,variableName = expression]; 

/' AIH"  int

amount = 123; float price = 12.0f; double x = 4.0, y = 2.5;

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("'  $!$D,@/$H'61'(9I2='&,B61='4"5H'      

 

public class VariableAssignDemo { public static void main(String args[]) { int x,y; boolean b1; float z = 3.414f; /* The program will not be compiled successfully if a character f is missing */ double w; x = 5;  y = 4; b1 = (x > y);  w = x * 3.2; = " + x + " y = " + y);  System.out.println("x System.out.println("b1 = " + b1);  System.out.println("z = " + z + " w = " + w); } }

   $!$W##,-LE G%B 52.'11'((,"!:(<1(0 %BQ 

" 1  1'(:(1')H'6 9%B ">'?'.'@' ='G52!5$1'(9&H%$E @A(E5 :(1')I7B/!5$0%(:M <++5,6"%8

final

4"2'='&,B6

[modifier] final dataType CONSTANT_NAME = expression; 

!5$ %B 





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CONSTANT_NAME

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expression

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C/6H'6 %B D,@/$H'6IH"='&,B6 final int 

MINIMUM = 4; final double MIN_GPA = 2.00;

:;"1'(:(1')H'6 %B  MINIMUM9420%I"A5C2/0M#:;" int!5$0%H':;"u<# H'6 %BMIN_GPA9420%I"A5C2/0M#:;"double!5$0%H':;"Qmm H'6 .%B 1='4"5H'G52-%$6(,865%$@ !5$.D2/60%1'(1='4"5H'1H/" %B.0%1'( (%$19I26'"RSB607B/1='4"5H'<#2@.G0H&'0'(*:#%B$"<:#6H'G52 !:(<1(0 %B Qc :;"D,@/$H'6 <%B &561'(:(1')H'6 %B<#1'(9I2H'6 %B RSB6.942 W##,-LE5,6<&569"(M: %BQc 

("'  $!%D,@/$H'6<&561'(:(1')H'6 %B public class ConstantDemo { public static void main(String args[]) { final int MAXIMUM = 10; final double MIN_GPA; System.out.println("Maximum is " + MAXIMUM); MIN_GPA = 2.00; System.out.println("Minimum GPA is " + MIN_GPA); MIN_GPA = 3.00; //illegal

// } }



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double

0.0

char

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null

 &='4(,+H'6 %B4(7/D,@<:( %B/$M>H '$9"+#K/1C/60L/5 .0%C/+CD1'(9I26'"/$MH >'$9"+#K/1 H'",8" !:(<1(0 %B Qu <&56D,@/$H'6D,@<:( %B :;"3#,1?C/6//:.K<# D,@<:( %B :;"D,@<:(>'$9" !5$!:(<1(0"%08 %D@, <:(i %B :;"3#,1?C/6//:.K&H@"D,@ <:( j <# k 9"0L/5 method1() :;"D,@<:(>'$9" <#D,@<:( j 9"0L/5 method2()1K:;"D,@<:(>'$9"/%1D,@4"SB6('G0H&'0'(* %B.(%$19I2D@ , <:(k"/10L/5 method1()G52 "/1.'1"%D 8 ,@<:( j 9"0L/5 ,86&/6.*7/@H':;"D,@<:("#D,@1,"  





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 ("'  $!,D,@/$H'6<&56C/+CDC/6D,@<:( public class VariableScopeDemo { public int i; // object variable public void method1() { int j = 4; // local variable int k = 2; // another local variable } public void method2() { int j = 0; //local variable System.out.println(i); // calling an object variable i //

System.out.println(k);

// illegal

} }

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("'  $!- D,@/$H'6<&56D,@<:(>'$9"<#D,@<:(C/6//:.K  public class ScopeExample { private int i=1;   public void method1() { int i=4, j=5;   this.i = i+j; method2(7);  }  public void method2(int i) { int j=8;  this.i = i+j; }   }------------------------------------------------------ public class TestScoping { public static void main(String args[]) {  ScopeExample scope = new ScopeExample(); scope.method1();  }  }   



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int x = (int)(Math.random()*10); int y,z; if(x > 5){ y = 6; } z = x+y;

}

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%=

x %= 3;

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public class BooleanDemo { public static void main(String args[]) { int x = 5;  int y = 4; boolean b1;  b1 = (x != y);  System.out.println("x not equal y is " + b1);  System.out.println("y less than 0 is " + (y < 0)); } }





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public class PromotionDemo {  public static void main(String args[]) { int i;  long l;  float fl = 4.2f; i = 4;  l = i;  fl = i; double x = fl;  fl = 4.2; //illegal  }  }





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String s1 = “This”; String s2 = s1+ “ is a test ”; String s3 = s1+4;

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static int abs(int x);



static long abs(long x);



static float abs(float x);



static double abs(double x);



static double acos(double x);



static double asin(double x);



static double atan(double x);



static double atan2(double x, double y);



static double ceil(double x);



static double cos(double x);

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static double exp(double x);



static double floor(double x);



static double log(double x);



static int max(int x, int y);



static long max(long x, long y);



static float max(float x, float y);



static double max(double x, double y);



static int min(int x, int y);



static long min(long x, long y);



static float min(float x, float y);



static double min(double x, double y);



static double pow(double x, double y);



static double random();



static double rint(double x);



static int round(float x);



static long round(double x);



static double sin(double x);



static double sqrt(double x);



static double tan(double x);



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public class PrintDemo {  public static void main(String args[]) {  int x = 3, y = 4, z = 5;  System.out.print("x = "+x); System.out.println(" y = "+y);  System.out.println("z = "+z);  } } 

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