String methods – matches and regionMatches

In this post, we will discuss about the String methods – matches and regionMatches.

boolean matches(String regex):

It returns true if String matches the given regular expression.

regex – the regular expression to which this string is to be matched.

It throws PatternSyntaxException – if the regular expression’s syntax is invalid.

public class ExampMatches {
	public static void main(String[] args) {
		
		String ip = "This is a house";
		
		System.out.println(ip.matches(".* is .*"));  // returns true 
		System.out.println(ip.matches(".* are .*"));  // returns false 	
	}
}

regionMatches():

This method tests if 2 string are equal or not. It is implemented in 2 ways.

1. boolean regionMatches(int toffset,String other,int ooffset,int len)
2. boolean regionMatches(boolean ignoreCase,int toffset,String other,int ooffset,int len)

boolean regionMatches(int toffset,String other,int ooffset,int len):

A substring of the String object is compared to a substring of the another string. The result is true if these substrings represent identical character sequences.

public class ExampRegionMatches {
	public static void main(String[] args) {
		
		String str1 = "This is a house";
		String str2  = "This";
				
		System.out.println(str1.regionMatches(0, str2, 0, 4));  // returns true .compare this
		System.out.println(str1.regionMatches(5, str2, 0, 4));  // returns false starts from 5th char
	}
}

Output:
true
false
[/su_note]