package com.web;
import java.util.ArrayList;
public class Test39 {
public static void main(String[] args) {
ArrayList arrayList = new ArrayList();
arrayList.add("a");
arrayList.add('c');
arrayList.add(true);
arrayList.add(5);
System.out.println(arrayList);//[a, c, true, 5]各种类型都可以存进去,但取出来时容易报错,用泛型<>事先指定类型
double[] arr = new double[4];
arr[0]= 1.2;
arr[1]=1;
arr[2]=2;
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i]);
//1.2
//1.0
//2.0
//0.0 默认加上去的
}
boolean[] arr2 = {
true,false,true,true};
for (boolean b : arr2) {
System.out.println(b);
}
//true
//false
//true
//true
Object[] arr3 = {
new Object(),new Object(),new Object()};
for (int i = 0; i < arr3.length; i++) {
System.out.println(arr[i]);
}//不知道为啥输出了数字
//1.2
//1.0
//2.0
}
}
ArrayList,数组中的存储类型
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转载自blog.csdn.net/djydjy3333/article/details/121510714
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