下列程序 test 类中的变量 c 的最后结果为() 。public class test{public static void main(String args[]){int a=10;int b;int c;if(a>50) {b=9;}c=b+a;}}

A. 10
B. 0
C. 19
D. 编译出错

变量x、y和z的定义：int x=10,y=20,z=30; 则表达式 x> y ? (x> z ? x : y) : (y> z ? y : z) 的值是（）。

A. 10
B. 20
C. 30
D. 表达式错误

下面程序运行输出的结果是（）public class Test1 {public static void main(String[] args) {int x=4 ;System.out.println("value is "+(x>4?99.9:9));}}

A. value is 99.9
B. value is 9
C. value is 9.0
D. 99

下列程序标注的【代码1】，【代码2】的输出结果是什么？（答案格式：【代码1】：_____。【代码2】：_____。）public class E {public static void main(String args[]) {int [] a={10,20,30,40},b[]={{1,2},{4,5,6,7}};b[0] = a;b[0][1] = b[1][3];System.out.println(b[0][3]); //【代码1】System.out.println(a[1]); //【代码2】}}

下列程序标注的【代码1】，【代码2】的输出结果是什么？（答案格式：【代码1】：_____。【代码2】：_____。）public class E {public static void main (String args[ ]){long[] a = {1,2,3,4};long[] b = {100,200,300,400,500};b = a;System.out.println("数组b的长度:"+b.length); //【代码1】System.out.println("b[0]="+b[0]); //【代码2】}}

下列程序的输出结果是_____。public class E {public static void main (String args[ ]) {char x='你',y='e',z='吃';if(x>'A'){y='苹';z='果';}elsey='酸';z='甜';System.out.println(x+","+y+","+z);}}

下列程序的输出结果是public class E {public static void main (String args[ ]) {char c = '\0';for(int i=1;i<=4;i++) {switch(i) {case 1: c = 'J';System.out.print(c);case 2: c = 'e';System.out.print(c);break;case 3: c = 'p';System.out.print(c);default: System.out.print("好");}}}}

下列程序的输出结果是public class E {public static void main (String []args) {int x = 1,y = 6;while (y-->0) {x--;}System.out.print("x="+x+",y="+y);}}

下列程序的输出结果是public class Sum {public static void main( String args[]) {double sum = 0.0 ;for ( int i = 1; i<= 38; i ++ )sum += i;System.out.println( "sum=" + sum );}}

下列程序的输出结果是public class ArrayAdd {public static void main(String args[ ]) {int i, s = 0;int a[] = {10, 20, 30, 40, 50, 60, 70, 80, 90};for ( i = 0 ; i < a.length; i++ )if(a[i] % 3 == 0) s += a[i];System.out.println("s=" + s);}}