Java String,char,int类型的相互转换

public static void main(String[] args) {
        //int -> string
        int testInt = 10;

        String testString1 = testInt + "";
        System.out.println("string1:  " +testString1);

        String testString2 = String.valueOf(testInt);
        System.out.println("string2:  " +testString2);

        String testString3 = Integer.toString(testInt);
        System.out.println("string3:  " +testString3);
}

输出结果：

string1:  10
string2:  10
string3:  10

public static void main(String[] args) {
        //int -> char
        int testInt = 4;

        char testChar1 = (char) (testInt + '0');
        System.out.println(testChar1);

        //代表10进制
        int radix = 10;
        char testChar2 = Character.forDigit(testInt, radix);
        System.out.println(testChar2);
}

输出结果：

4
4

public static void main(String[] args) {

        //string -> int
        String testString = "520";

        int testInt1 = Integer.parseInt(testString);
        System.out.println("int1:  " +testInt1);

        int testInt2 = Integer.valueOf(testString);
        System.out.println("int2:  " +testInt2);

}

输出结果为：

int1:  520
int2:  520

public static void main(String[] args) {

        // string -> char
        String testString = "abcdefg";

        //获取某个下标的字符元素
        char ch = testString.charAt(0);
        System.out.println("ch:   " + ch);

        //string转 char array
        char chArray[] = testString.toCharArray();
        System.out.println("ch:   " + chArray[0]);
    }

输出结果为：

ch:   a
ch:   a

public static void main(String[] args) {

        // char转 int
        char ch = '9';

        int testInt1 = Character.getNumericValue(ch);

        int testInt2 = (int)ch - (int)'0';

        System.out.println("int:    "+ testInt1);
        System.out.println("int:    "+ testInt2);

    }

输出结果：

int:    9
int:    9

public static void main(String[] args) {

        // char转 string
        char ch = 's';

        String testString1 = String.valueOf(ch);
        System.out.println("string:    "+ testString1);

        String testString2 = ch + "";
        System.out.println("string:    "+ testString2);

        String testString3 = Character.toString(ch);
        System.out.println("string:    "+ testString3);

        String testString4= String.valueOf(new char[]{'j', 'a', 'v', 'a'});
        System.out.println("string:    "+ testString4);

    }

输出结果为：

string:    s
string:    s
string:    s
string:    java