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:Â
- String matches() Method
- String regionMatches()
- 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.Â
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 classÂ
// Main classpublic class GFG {Â
    // Main driver method    public static void main(String args[])    {Â
        // Declaring and initializing a string        // Input string        String Str = new String("Welcome to neveropen");Â
        // 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(.*)"));Â
        // Display message for better readability        System.out.print(            "Does String contains regex geeks ? : ");Â
        // Testing if regex is present or not        System.out.println(Str.matches("geeks"));    }} |
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 classÂ
// Main classpublic class GFG {Â
    // Main driver method    public static void main(String args[])    {        // Declaring and initializing a string        String Str1            = new String("Welcome to neveropen");Â
        // Initializing test string        String Str2 = new String("GEEKS");Â
        // Tests whether GEEKS starts in neveropen        // starting from pos 11 and        // compares 5 characters of GEEKS        System.out.print(            "Checking if GEEKS is in neveropen( case sensitive ) : ");        System.out.println(            Str1.regionMatches(11, Str2, 0, 5));    }} |
Checking if GEEKS is in neveropen( 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.Â
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:Â 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()Â
// Main classpublic class GFG {    // Main driver method    public static void main(String args[])    {        // Declaring and initializing a string        String Str1            = new String("Welcome to neveropen");Â
        // Initializing a test string        String Str2 = new String("GEEKS");Â
        // Tests whether GEEKS starts in neveropen        // 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 neveropen( case insensitive ) : ");Â
        System.out.println(            Str1.regionMatches(true, 11, Str2, 0, 5));    }} |
Checking if GEEKS is in neveropen( case insensitive ) : true
