下列程序的运行结果sum的值为()Int i=1,sum=0;While(i<=10){if(i>=5) break;sum+=i;i++;}System.out.println(“sum结果为”+sum)
A.9
B.10
C.11
D.12
10
A.9
B.10
C.11
D.12
10
A.50,30
B.30,50
C.80,-20
D.80,20
A.5,4
B.5,4.8
C.3,4.6
D.3,4
A.12
B.14
C.15
D.13
class A
{
int a;
A(int b)
{a=b;}
void show()
{System.out.println(“a=”+a);}
}
public class Class1
{
public static void main (String args[])
{
A bj=new A(12345);
boolean b=false;
char ch=97;
obj.show();
System.out.println(“b=”+b+”/tch=”+ch);
}
}
下面程序的主线程创建10个线程,它们都取变量的值,经累加后,将新值存回到变量且要求结果正确。
class MyResourceClass
{
int IntegerResource;
MyResourceClass(){IntegerResource=0;}
public int getInfo(){return IntegerResource;}
public void putInfo(int info){IntegerResource=info;}
()Void sumResource(int q)
{
int LocalInteger;
LocalInteger=getInfo();
LocalInteger+=q;
putInfo(LocalInteger);
}
}
class MyMultiThreadClass implements Runnable
{
MyResourceClass UseInteger;
MyMultiThreadClass(MyResourceClass mrc)
{
UseInteger=mrc;
}
public void run()
{
for(int i=0;i<100;i++)
{
UseInteger.sumResource(50);
}
}
}
public class Class30
{
public static void main(String[] args)
{
MyResourceClass mrc=new MyResourceClass();
Thread aThreadArray[]=new Thread[10];
System.out.println(mrc.getInfo());
System.out.println("wait...");
for(int i=0;i<10;i++)
{
aThreadArray[i]=new Thread(new MyMultiThreadClass(mrc));
aThreadArray[i].();
}
whileLoop;
while(true)
{
for(int i=0;i<10;i++)
if(aThreadArray[i].isAlive())continue whileLoop;
break;
}
System.out.println("jieguo="+mrc.getInfo());
}
}
A.结果:1到100之和为:5000
B.结果:1到100之和为:0
C.结果:1到100之和为:2050
D.结果:1到100之和为:5020