String matches() Method in Java with Examples

Variants of matches() method is used to tell more precisely not test whether the given string matches to a regular expression or not as whenever this method is called in itself as matches() or be it matches() where here we do pass two arguments that are our string and regular expression, the working and output remains same.

Variants of String matches() Method

There exist multiple variants three variants of the matches() method, as listed and described below, as follows: 

1. String matches() Method
2. String regionMatches()
3. String regionMatches() with ignoreCase

1. String matches() Method

This method tells whether or not this string matches the given regular expression. An invocation of this method of the form str.matches(regex) yields exactly the same result as the expression Pattern.matches(regex, str).

Syntax of String matches() method

public boolean matches (String regex)

Parameters

• regex: The regular expression to which this string is to be matched. 

Return Type

• Boolean value, returning true if and only if strings match the given regular expression else false.

Example of String matches() Method

Java

// Java Program to Demonstrate Working of matches() Method
// of String class

// Main class
public class GFG {

    // Main driver method
    public static void main(String args[])
    {

        // Declaring and initializing a string
        // Input string
        String Str = new String("Welcome to geeksforgeeks");

        // Display message for better readability
        System.out.print(
            "Does String contains regex (.*)geeks(.*) ? : ");
        // Testing if regex is present or not
        System.out.println(Str.matches("(.*)geeks(.*)"));

        // Display message for better readability
        System.out.print(
            "Does String contains regex geeks ? : ");

        // Testing if regex is present or not
        System.out.println(Str.matches("geeks"));
    }
}

Output

Does String contains regex (.*)geeks(.*) ? : true
Does String contains regex geeks ? : false

2. String regionMatches() Method

This method has two variants that can be used to test if two string regions are equal.

Syntax of regionMatches() Method

public boolean regionMatches(int str_strt, String other, int other_strt,int len)

Parameters

• The starting offset of the subregion in this string
• The string argument
• The starting offset of the subregion in the string argument
• The number of characters to compare

Return Type

Boolean value, true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise.

Example of regionMatches() Method

Java

// Java Program to Demonstrate Working of regionmatches()
// method of String class

// Main class
public class GFG {

    // Main driver method
    public static void main(String args[])
    {
        // Declaring and initializing a string
        String Str1
            = new String("Welcome to geeksforgeeks");

        // Initializing test string
        String Str2 = new String("GEEKS");

        // Tests whether GEEKS starts in geeksforgeeks
        // starting from pos 11 and
        // compares 5 characters of GEEKS
        System.out.print(
            "Checking if GEEKS is in geeksforgeeks( case sensitive ) : ");
        System.out.println(
            Str1.regionMatches(11, Str2, 0, 5));
    }
}

Output

Checking if GEEKS is in geeksforgeeks( case sensitive ) : false

3. String regionMatches() with ignoreCase

This method has two variants that can be used to test if two string regions are equal. 

Syntax of String regionMatches()

public boolean 
regionMatches(boolean ignoreCase, int str_strt, String other, int other_strt,int len)

Parameters

• The starting offset of the subregion in this string
• The string argument
• The starting offset of the subregion in the string argument
• The number of characters to compare
• ignoreCase:  If true, ignore the case when comparing characters

Return Type

It returns true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise. Whether the matching is exact or case insensitive depends on the ignoreCase argument.

Example of regionMatches() with ignoreCase

Java

// Java Program to Demonstrate
// Working of regionmatches()

// Main class
public class GFG {
    // Main driver method
    public static void main(String args[])
    {
        // Declaring and initializing a string
        String Str1
            = new String("Welcome to geeksforgeeks");

        // Initializing a test string
        String Str2 = new String("GEEKS");

        // Tests whether GEEKS starts in geeksforgeeks
        // starting from pos 11 and from 0 ( i.e starting in
        // GEEKS) and ignores case and compares 5 characters
        // of GEEKS
        System.out.print(
            "Checking if GEEKS is in geeksforgeeks( case insensitive ) : ");

        System.out.println(
            Str1.regionMatches(true, 11, Str2, 0, 5));
    }
}

Output

Checking if GEEKS is in geeksforgeeks( case insensitive ) : true