数组、字符串、集合的相互转换

数组、字符串、集合的相互转换

1.数组转字符串

public static void main(String[] args) {
		// 定义一个数组
		char[] a = {'a','b','c','d'};
		String b = new String(a);
		System.out.println(b);// abcd
	}

2.数组转集合

public static void main(String[] args) {
		// 定义一个数组
		Integer[] a = {1,2,3,4};
		List list = Arrays.asList(a);
		System.out.println(list);//[1,2,3,4]
	}

3.字符串转数组

public static void main(String[] args) {
		String str ="asdfg";
	    char[] a = str.toCharArray();
	    System.out.println(a);//asdfg
	}

4.字符串转集合

public static void main(String[] args) {
		String str ="a,s,d,f,g";
	    List list = Arrays.asList(str.split(","));
	    System.out.println(list);// [a, s, d, f, g]
	}

5.集合转数组

public static void main(String[] args) {
        List list = new ArrayList();
        list.add('a');
        list.add(1);
        list.add('c');
        Object[] a = list.toArray();
        System.out.println(Arrays.toString(a));// [a, 1, c]
    }

6.集合转化为字符串

 public static void main(String[] args) {
        List list = new ArrayList();
        list.add("张三");
        list.add("李四");
        String s = StringUtils.join(list, "");
        System.out.println(s);//张三，李四
    }