JAVA基础测试题
班级 姓名 分数
1.下面程序的输出是什么
public class J_Class {
static int m_data=0;
}
public class J_Test {
public static void main(String args[]) {
J_Class a=new J_Class();
J_Class b=new J_Class();
a.m_data=1;
b.m_data=2;
System.out.println(a.m_data);
} }
A 0 B 1 C 2 D 编译错误
2.下面程序的输出是什么
class J_Base {
public int m_data=1;
public String mb_method(){
return “2″;
} }
public class J_Test extends J_Base{
public int m_data=3;
public String mb_method(){
return “4″;
}
public static void main(String args[]) {
J_Base app=new J_Test();
System.out.println(app.m_data+app.mb_method());
} }
A 12 B 14 C 32 D 34
3.下面程序的输出结果是
public class J_Test {
public static void main(String args[]) {
int i = 99;
mb_operate(i);
System.out.println(i+100);
}
static void mb_operate(int i){
i+=100;
} }
A 99 B 199 C 299 D 99100
4.下面哪段代码可以通过编译并正常运行
A Character c=new Character(‘x’);
B int primitive=1234;
Integer wrappendInt=new Integer(primitive);
C Boolean wB=new Boolean(“junk”);
D Long wLong=new Long(“here”);
5.已知：Integer a=new Integer(0);Integer b =new Integer(0);Long c=new Long(0);下面哪些表达式返回true
A a==b B a.equals(b) C a.equals(c) D a.equals(0)
6.下面程序的输出是
public class J_Test {
public static void main(String args[]) {
String s[]={“1″,”2″};
mb_swap(s[0],s[1]);
System.out.println(s[0]+s[1]);
}
static void mb_swap(String s0,String s1){
String t=s0;
s0=s1;
s1=t;
} }
7.下面程序的输出是
public class J_Test {
public static void main(String args[]) {
String s[]={“1″,”2″};
mb_swap(s);
System.out.println(s[0]+s[1]);
}
static void mb_swap(String s[]){
String t=s[0];
s[0]=s[1];
s[1]=t;
} }
8.下面程序段被执行后，s2的值是 ,s2的值是 ，s3的值是 ，b的值是
String s1=”12″;
String s2=s1.concat(“34″);
String s3=s1+”34″;
boolean b=(s2==s3);
9.下面程序运行后s1的值为 ，s2的值为
String s1=”abc”;
String s2=”def”;;;
s2.toUpperCase();
s1.concat(s2);
10.下面的程序的运行结果是a为 ，b为
public class J_Test {
public static void main(String args[]) {
String a=new String(“java”);
StringBuffer b=new StringBuffer(“java”);
mb_method(a,b);
}
public static void mb_method(String s,StringBuffer t){
s.replace(‘j’, ‘i’);
t=t.append(“C”);
} }
11.填写空白的位置，使整个表达式完整
void mb_method() {
new Exception(“Exception i mb_mb_method”);
}
12.下面程序输出
public class J_Test {
public static void main(String args[]){
try{
System.out.print(“1″);
if(true){return;}
}catch (RuntimeException e) {
System.out.print(“2″);
return;
}catch (Exception e2) {
System.out.print(“3″);
return;
}finally{
System.out.print(“4″);
}
System.out.print(“End!”);
} }
13.下面程序输出
public class J_Test {
public static void main(String args[]){
int i=0;
try{
for(i=0;i<10;i++){
try{
if(i%3==0){
throw new Exception();
}
System.out.print(“1:”+i+”,”);
}catch (Exception e2) {
System.out.print(“2:”+i+”,”);
i+=2;
if(i%3==2)
throw new Exception();
return;
}finally{
i*=2;
System.out.print(“3:”+i+”,”);
}
System.out.print(“End!”);
}
}catch (Exception e2) {
System.out.print(“4:”+i+”,”);
return;
}finally{
System.out.print(“5:”+i+”,”);
}
System.out.print(“End!”);
} }
14.下面哪些语句会发生编译错误
A int []a; B int []b=new int[10];
C int c[]=new int[]; D int d[]=null;
15.下面哪些语句会发生编译错误
A int [10]a; B int [10]b=new int[5];
C int c[10]=new int[10]; D int d[10]=nu