[Java] String padding

If you want to pad the string to the specified number of digits, use the ** "String.format" ** method.

String.format

Blank padding for strings

`padding.java`


import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        String result5keta = blankPadding5keta();
        String result10keta = blankPadding10keta();
        System.out.println(result5keta);
        System.out.println(result10keta);
    }

    //Fill with 5 digits
    private static String blankPadding5keta(){
        String str = "123";
        String paddingStr = str.format("%5s", str);

        return paddingStr;
    }

    //Fill in blanks with 10 digits
    private static String blankPadding10keta(){
        String str = "12345";
        String paddingStr = str.format("%10s", str);

        return paddingStr;
    }
}

`result`


  12345
     12345

Zero padding of string

`padding.java`


import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        String result5keta = zeroPadding5keta();
        String result10keta = zeroPadding10keta();
        System.out.println(result5keta);
        System.out.println(result10keta);
    }

    //Fill with 0 in 5 digits
    private static String zeroPadding5keta(){
        String str = "123";
        String paddingStr = str.format("%5s", str).replace(" ", "0");
        
        return paddingStr;
    }

    //Fill with 0 in 10 digits
    private static String zeroPadding10keta(){
        String str = "12345";
        String paddingStr = str.format("%10s", str).replace(" ", "0");
        
        return paddingStr;
    }
}

`result`


00123
0000012345