Java validate integer user input

Sometime, when we play with user input, we want to validate the input value is specific to certain data type. For example, you have a simple java program that query for user's age. Like we know age is in integer data type. So how to handle if a user put his age something like this, "fifty" or 50.34. This is impossible right? But if the user want to test the robustness of your system from error handling view, this is not impossible.Now i want to share with you, how you can handle this in a simple java program that run through command prompt.The basic idea is, if a user put other than integer value, our program will throw an exception. So, we will put our code that tell user what he/she do is wrong in the exception block.In other tutorial, i will share with you how to create your own exception handling.

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COMPLETE SOURCE CODE FOR : ValidateIntegerInput.java
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import java.util.Scanner;
import java.util.InputMismatchException;

public class ValidateIntegerInput
{
 public static void main(String[]args)
 {
  boolean benchmark=true;
  while(benchmark)
  {
   Scanner a=new Scanner(System.in);
  
   try
   {
    System.out.println("Put 0 to exit");
    System.out.println("What is your age?");
   
    //nextInt will throw InputMismatchException
    //if the next token does not match the Integer  
    //regular expression, or is out of range 
    int b=a.nextInt();
    if(b==0)
    {
     benchmark=false;
    }
    else
    {
     System.out.println("Your age is : "+b);
    }
   }
   catch(InputMismatchException exception)
   {
    //Print "This is not an integer"
    //when user put other than integer
    System.out.println("Please put integer value");
   }
   catch(Exception exception)
   {
    exception.printStackTrace();
   }
  }
 }
}

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JUST COMPILE AND EXECUTE IT
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Read integer user input in java

Complete source code below, will show you how to wait and read integer user input in command prompt.

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COMPLETE SOURCE CODE FOR : ReadIntegerUserInput.java
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import java.util.Scanner;

public class ReadIntegerUserInput
{
public static void main(String[]args)
{
 try
 {
  //Create a scanner object
  //Scanner is a predefined class in java that will be use to scan text
  //System.in is mean, we will receive input from standard input stream
  Scanner readUserInput=new Scanner(System.in);

  //Print into command prompt(What is your age ?)
  System.out.println("What is your age ?");

  //Wait and READ INTEGER INPUT from user after user hit 'Enter'
  int myAge=readUserInput.nextInt();

  //Print what store in myAge
  System.out.println("Your age is : "+myAge);
 }
 catch(Exception exception)
 {
  //Error that will be print if user put other than number include
  //point number
  System.out.println("Hey !!! Don't put other than number");
 }
}
}

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JUST COMPILE AND EXECUTE IT
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Source code to convert integer to string in java

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COMPLETE SOURCE CODE FOR : ConvertIntegerToString.java
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public class ConvertIntegerToString
{
 public static void main(String[]args)
 {
  int sampleNumber=123;
  
  //Convert integer to string
  String stringForNumber=Integer.toString(sampleNumber);
  
  System.out.println(stringForNumber);
 }
}

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JUST COMPILE AND EXECUTE IT
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