Java – String trim() and hashCode() Methods

In this  tutorial we will discuss about trim() and hashCode() methods. Lets discuss about trim() first: It returns a String after removing leading and trailing white spaces from the input String. For e.g. "     Hello".trim() would return the String "Hello".

public String trim()

Example: trim() method

public class TrimExample{
   public static void main(String args[]){
       String str = new String("    How are you??   ");
       System.out.println("String before trim: "+str);
       System.out.println("String after trim: "+str.trim());
   }
}

Output:

String before trim:     How are you??   
String after trim: How are you??

hashCode() method

This method returns the hash code for the String. The computation is done like this:

s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

Syntax of this method:

public int hashCode()

Example: hashCode() method

public class HashCodeExample{
   public static void main(String args[]){
       String str = new String("Welcome!!");
       System.out.println("Hash Code for String str: "+str.hashCode());	      
   }
}

Output:

Hash Code for String str: 1601728226

References:

1. HashCode JavaDoc
2. hashCode() JavaDoc
3. trim() JavaDoc