Java - convert int to String

In Java, we can convert int to String in couple of different ways.

Short solutions:

// solution 1
String str1 = String.valueOf(123); // 123

// solution 2
String str2 = Integer.toString(123); // 123

// solution 3
String str3 = "" + 123; // 123

1. Using String.valueOf()

public class Example1 {

    public static void main(String[] args) {
        int num = 123;
        String str = String.valueOf(num);
        System.out.println(str); // 123
    }
}

Output:

123

2. Using Integer.toString()

public class Example2 {

    public static void main(String[] args) {
        int num = 123;
        String str = Integer.toString(num);
        System.out.println(str); // 123
    }
}

Output:

123

3. Using "" + 123

public class Example3 {

    public static void main(String[] args) {
        int num = 123;
        String str = "" + num;
        System.out.println(str); // 123
    }
}

Output:

123

4. Using String.format()

public class Example4 {

    public static void main(String[] args) {
        int num = 123;
        String str = String.format("%d", num);
        System.out.println(str); // 123
    }
}

Output:

123

5. Using StringBuilder

public class Example5 {

    public static void main(String[] args) {
        int num = 123;
        StringBuilder sb = new StringBuilder();
        sb.append(num);
        String str = sb.toString();
        System.out.println(str); // 123
    }
}

Output:

123

The same can be applied to StringBuffer

6. Using DecimalFormat

import java.text.DecimalFormat;

public class Example6 {

    public static void main(String[] args) {
        int num = 123;
        DecimalFormat df = new DecimalFormat("#");
        String str = df.format(num);
        System.out.println(str); // 123
    }
}

Output:

123

7. Using DecimalFormat with floating point pattern

import java.text.DecimalFormat;

public class Example7 {

    public static void main(String[] args) {
        int num = 12345;
        DecimalFormat df = new DecimalFormat("#,##0");
        String str = df.format(num);
        System.out.println(str); // 12,345
    }
}

Output:

12,345

References

1. Integer.toString(int)
2. String.valueOf(int)
3. String.format(java.lang.String,java.lang.Object...)
4. StringBuilder.append(int)
5. DecimalFormat.format(long)
6. Type conversion - wik

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