Converting specific letters to lowercase in Java

Question

Suppose I have a String in java with the value "hELLo".

How do I convert it into "heLLo" (The second character must be lowercase) ?

Answer 1

There are lot more other ways, but best would be to have a good read at few articles or this.

As simple as that, use java.lang.String#replace

public static void main(String[] args) {
        String original = "hELLo";
        String modified = original.replaceFirst("E" , "e");
        System.out.println(modified);
    }

output

heLLo

You can also use replaceAll, for replacing all occurrences of letter.

Edit - Replace 2nd char always

public static void main(String[] args) {
        String original = "hELLo";
        char secondChar = original.charAt(1);
        String modified = original.replaceFirst(String.valueOf(secondChar) , String.valueOf(secondChar).toLowerCase());
        System.out.println(modified);
    }

output

heLLo

Using String substring

public static void main(String[] args) {
        String original = "hELLo";
        String secondChar = original.substring(1,2);
        String modified = original.replaceFirst(secondChar , secondChar.toLowerCase());
        System.out.println(modified);
    }

Answer 2

    String str = "hELLo";
    String str1 = str.replace("E","e");

use replace() of String class

Answer 3

String str = "hELLo";
String str1 = str.replace("E","e");

use replace() of String class