1,2
1 Java, , ,
.
:
Java;
Java;
/;
;
J2SE:
- java.lang.Integer, java.lang.Double, java.lang.Float;
java.lang.Exception;
java.lang.Math;
, - - java.io.InputStreamReader, java.io.InputStream, java.io.PrintStream
1. : , , , , , . , , . , :
public static int getSumNumbers(int[] numbers);
2. 1, , Double, , 1, . main . , , .
3. , 2, , .
4. , , , , . , , .
5. , .
6. , , 1-5.
1. . ?
public void doSomething(){
int x;
double y;
x=(int)Math.random();
y=Math.ceil((double)(int)Math.random());
do{
System.out.println(x/y);
} while (x<y);
}
2. ?
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|
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1. public final abstract int doAnything();
2. public abstract int doA(int j);
3. public private void notC(boolean flag);
4. final abstract boolean isEqual(float c, float d);
1. 4.
2. ?
3. , ?
4. ?
5. Java?
2 Java, ,
:
Java, ;
, ;
;
;
;
java.lang.Math ;
, , , , .
J2SE:
- java.lang.Integer,java.lang.Double, java.lang.Float;
java.lang.Exception;
java.lang.Math;
1. , , , :
/ ,
/ ,
/ .
. int. , double. :
/**
@param angles ;
@param type - ,
@return ;
*/
public static double getSumSinuses(double[] angles, int type);
2. , .
3. , , , .
4. , . , .
5. , .
1. :
package javaapplication2;
private class Sample {
private static int value;
static{
value=1;
}
private int n;
Sample(){
value++;
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n=value%2;
}
Sample(int n){
this();
n=this.n;
}
public int getN(){
return(n<10?n=value++:n);
}
}
?:
/*
..
**/
public void test(){
for (int x=0;x<10;x++)
{
System.out.println(new Sample(x));
}
}
2.
?
1. public final int 1v=2;
2. public final int 'xxx'=2;
3. public final int \u1000=1000;
4. public final static volatile boolean bool=true;
5. static volatile Boolean v2=Boolean.parseBoolean("true");
1. .
2. ?
3. - .
4. -?
