exception handling in java null pointer

Code Example 1

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Code Example 2

/**
  * @param obj An optional foo for ____. May be null, in which case 
  *  the result will be ____.
  */
public void doSomething(SomeObject obj) {
    if(obj == null) {
       //do something
    } else {
       //do something else
    }
}

Code Example 3

// A Java program to demonstrate that invoking a method 
// on null causes NullPointerException 
import java.io.*; 
  
class GFG 
{ 
    public static void main (String[] args) 
    { 
        // Initializing String variable with null value 
        String ptr = null; 
  
        // Checking if ptr.equals null or works fine. 
        try
        { 
            // This line of code throws NullPointerException 
            // because ptr is null 
            if (ptr.equals("gfg")) 
                System.out.print("Same"); 
            else 
                System.out.print("Not Same"); 
        } 
        catch(NullPointerException e) 
        { 
            System.out.print("NullPointerException Caught"); 
        } 
    } 
}