int数组:
int[] ia = new int[2];
System.out.println(ia[0]);
System.out.println(ia[1]);
输出:
0
0
float数组:
float[] fa = new float[2];
System.out.println(fa[0]);
System.out.println(fa[1]);
输出:
0.0
0.0
double数组:
double[] da = new double[2];
System.out.println(da[0]);
System.out.println(da[1]);
输出:
0.0
0.0
char数组:
char[] ca = new char[2];
System.out.println( (int)ca[0] );
System.out.println( ca[0] ); // 空
System.out.println( (int)ca[1] );
System.out.println( ca[1] ); // 空
输出:
0
0
对象数组:
package me.letian;
public class HelloJava {
static class User {
private String name;
public User() {
this.name = "letian";
}
public String toString() {
return "Hi, I am " + this.name;
}
}
public static void main(String[] args) {
User[] users = new User[2];
System.out.println( users[0] );
System.out.println( users[1] );
users[0] = new User();
System.out.println( users[0] );
}
}
或者:
package me.letian;
public class HelloJava {
class User {
private String name;
public User() {
this.name = "letian";
}
public String toString() {
return "Hi, I am " + this.name;
}
}
public static void main(String[] args) {
HelloJava hj = new HelloJava();
User[] users = new User[2];
System.out.println( users[0] );
System.out.println( users[1] );
users[0] = hj.new User();
System.out.println( users[0] );
}
}
null
null
Hi, I am letian