How to replace string with another string in java Program -

public class ReplaceAllExample2 {
  public static void main(String args[]) {
    String s1 = "My name is Rajendra. My name is Sarvam. My name is TechSarvam.";
    String replaceString = s1.replaceAll("is", "was"); //replaces all occurrences of "is" to "was"
    System.out.println(replaceString);
  }
}

Step-by-Step Breakdown:

1. Class and Method Declaration:

public class ReplaceAllExample2

{

public static void main(String args[])

{

The program declares a class ReplaceAllExample2.
The main method is the entry point where execution begins.

2. String Declaration:

String s1 = “My name is Rajendra. My name is Sarvam. My name is TechSarvam.”;

A String variable s1 is declared and assigned the string value “My name is Rajendra. My name is Sarvam. My name is TechSarvam.”

3. Using replaceAll() Method:

String replaceString = s1.replaceAll(“is”, “was”);

The call to the method replaceAll(“is”, “was”) will replace all occurrences of the string “is” with the string “was”.

The replaceAll() method takes two arguments:

The first argument: The string to be replaced (in this case, “is”).
The second argument: The string to replace the first one (in this case, “was”).
The method will find the entire string s1 and replace all its occurrences of “is” with “was”, wherever it may occur.

4. Printing the Result:

System.out.println(replaceString);

It will print out the modified string in the variable replaceString, which is the result of all “is”s replaced by “was”.

Example Explanation:

The input string s1 is:

” My name is Rajendra. My name is Sarvam. My name is TechSarvam.”

The replacement of words “is” and “was” through replaceAll(“is”, “was”) will replace the following lines.

“is” from “is Rajendra” to “was” and gets converted to “was Rajendra”.
“is” from “is Sarvam” to “was” and gets converted to “was Sarvam”.
“is” in “is TechSarvam” with “was”, so it becomes “was TechSarvam”.

Thus, the modified string will be:

“My name was Rajendra. My name was Sarvam. My name was TechSarvam.”

Program Output:

My name was Rajendra. My name was Sarvam. My name was TechSarvam.

Summary:

The function places all instances of the substring “is” in the original string s1 with the substring “was”.
The replaceAll() method is sensitive to case, therefore it will only replace the lowercase “is” and not “Is”, “IS” and the rest.