How to Replace a Substring of a String in Dart?

To replace all the substrings of a string, we make use of the replaceAll method in Dart. This method replaces all the substrings in the given string with the desired substring. Returns a new string in which the non-overlapping substrings matching from (the ones iterated by from.allMatches(this String)) are replaced by the literal string replace.

Syntax:

String_name.replaceAll ( Old_Sub_String , New_Sub_String );

In the above sequence:

• String_name is the name of the string in which the operation is to be done. It could be the string itself.
• Old_String_Pattern is the pattern present in the given string.
• New_String_Pattern is the new pattern that is to be replaced with the old pattern.

Image Representation:

Example 1: 

Replacing the substring in the given string.

// Main function
void main() {
    String gfg = "Welcome GeeksForGeeks";
    
    //replace substring of the given string
    String result = gfg.replaceAll("GeeksForGeeks", "Geek!");
    
    print(result);
}

Output:

Welcome Geek!

In the above example, the substring "GeeksForGeeks" is replaced by another string "Geek!".

Example 2:

Using chain of replaceAll() method to change the string in dart.

// Main function
void main() {
    String gfg = "Welcome GeeksForGeeks";
    
    //replace substring of the given string
    String result = gfg.replaceAll("GeeksForGeeks", "Geek!").replaceAll("!", " :)");
    
    print(result);
}

Output:

Welcome Geek :)

In the above example, the substring "GeeksForGeeks" is replaced by another string "Geek!" and then "!" is replaced by " : )".