Java String startsWith() Method with example

The startsWith() method of String class is used for checking prefix of a String. It returns a boolean value true or false based on whether the given string begins with the specified letter or word.

For example:

String str = "Hello";

//This will return true because string str starts with "He"
str.startsWith("He"); 

Java String startsWith() method

There are two variations of starsWith() method.

boolean startsWith(String str): It returns true if the String str is a prefix of the String.

boolean startsWith(String str, index fromIndex): It returns true if the String begins with str, it starts looking from the specified index “fromIndex”. For example lets say that the value of the String s is “Hi there” and we are calling starsWith() method like this – s.startsWith(“there”, 3) then this will return true because we have passed value 3 as fromIndex, the searching of keyword “there” begins from the index 3 of the given string s and it is found at the beginning of the string s.

A simple example of startsWith() method

This is a simple example where we have a string s and we are checking wether the string s starts with a particular word using startsWith() method.

public class JavaExample{  
   public static void main(String args[]){ 
	//given string
	String s = "This is just a sample string";  
		
	//checking whether the given string starts with "This"
	System.out.println(s.startsWith("This"));  
		
	//checking whether the given string starts with "Hi"
	System.out.println(s.startsWith("Hi"));  
   }
}

Output:

Java String startsWith() method example

Lets take an example where we are using both the variations of startsWith() method.

public class StartsWithExample{
   public static void main(String args[]) {
       String str= new String("quick brown fox jumps over the lazy dog");
       System.out.println("String str starts with quick: "+str.startsWith("quick"));
       System.out.println("String str starts with brown: "+str.startsWith("brown"));
       System.out.println("substring of str(starting from 6th index) has brown prefix: "
+str.startsWith("brown", 6));
       System.out.println("substring of str(starting from 6th index) has quick prefix: "
+str.startsWith("quick", 6));

   }
}

Output:

String str starts with quick: true
String str starts with brown: false
substring of str(starting from 6th index) has brown prefix: true
substring of str(starting from 6th index) has quick prefix: false