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JavaScript JavaScript Basics (Retired) Making Decisions with Conditional Statements Build a Random Number Guessing Game

Prakhar Patwa
Prakhar Patwa
11,260 Points

Build a Random Number Guessing Game

my code is

var randomNumber = Math.floor(Math.random() * 6) + 1 ; var guess = prompt("i am thinking the number between 1 and 6 , what it is?") if(parseInt(guess) === randomNumber){ document.write("<h1> You Guess The Right Number </h1>") }else if(!NaN){ document.write("<h1>you have entered the invalid entry " + guess + "</h1>") }else{ document.write("<h1>You Guess the wrong number,the random number was " +randomNumber+ "</h1>") }

I also want to show that suppose if user entered the string so it should show invalid entry . Every time it showing invalid entry even on integer.

1 Answer

Hey Prakhar,

I noticed in what I could gather from your code that you're checking if (!NaN). Your if statements should be almost always comprised of dynamic data. if (!NaN) is a static if-statement that will always evaluate to true because you are saying "If NaN is a falsey value, do this code." NaN will always be a falsey value, so the if statement always executes which is why you get the invalid entry message every time an incorrect guess has been made.

I reformatted your code and added a few things:

var randomNumber = Math.floor(Math.random() * 6) + 1 ;
//Added semicolon to guess
var guess = prompt("I am thinking of a number between 1 and 6.  What is it?");
//Added 10 to parseInt so that it will explicitly get the number inside guess from the base 10 system
if(parseInt(guess, 10) === randomNumber){ 
document.write("You Guessed The Right Number!") 
}
//Check to see if guess is not a number
else if (isNaN(guess)) { 
//Added semicolon
document.write("You have entered the invalid entry " + guess); 
}
else { 
//Added semicolon
document.write("You guessed the wrong number.  The random number was "+randomNumber);
 }
Prakhar Patwa
Prakhar Patwa
11,260 Points

okay i got it now..... in place of !Nan it should be written like isNaN(variable_name) thankx alott Marcus Parsons.

Absolutely, Prakhar! :) You are very welcome!