java 各种数据类型的互相转换

StringBuilder转化为String

    StringBuilder stb = new StringBuilder();
    String str=stb.toString();  //方法1
    String str=""+stb;  //方法2

​

String转化为StringBuilder

    String str = "abcdefghijklmnopqrs";
    StringBuilder stb = new StringBuilder(str);

整型数组转化为字符串

    StringBuilder s = new StringBuilder();
    for(i=1;i<=n;i++) {
        s.append(String.valueOf(a[i]));
    }
    String str = ""+s;
                    

字符串转化为整形数组

    String str="123456";
    int[] a = new int[str.length()];
    for(int i=0;i<str.length();i++) {
        a[i]  = str.charAt(i)-'0';
    }

​

字符串转化为字符数组

    String str="123456";
    char[] c = str.toCharArray() ;
    System.out.println(c);

​

字符数组转化为字符串

    char[] c = {'a','s','d','4','5',};
    String str = new String(c);
    System.out.println(str);

​

字符数组转化为整型数组

    char[] c = { '1', '2', '3', '4', '5', };
    int[] a = new int[c.length];
    for (int i = 0; i < 5; i++) {
        a[i] = c[i] - '0';
        System.out.println(a[i]);
    }

​

整型数组转化为字符数组

    int[] a = {1,2,3,4,5};
    char[] c = new char[a.length];
    for (int i = 0; i < 5; i++) {
        c[i] = (char) (a[i]+'0');
        System.out.println(c[i]);
    }

​
​

整型数转化为字符串

1.String str = Integer.toString(i);
2.String s = String.valueOf(i);
3.String s = "" + i;

字符串转化为整型数

int i = Integer.valueOf(str).intValue();