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JavaScript JavaScript Basics (Retired) Making Decisions with Conditional Statements Booleans

Posted by KORAXE IUHMAGEON
KORAXE IUHMAGEON
Courses Plus Student 8,486 Points

I typed parseInt() but it's giving me a parsing error

var correctGuess = false; var randomNumber = Math.floor(Math.random() * 6) +1; var guess prompt('I am thinking of a number between 1 and 6. What is it?'); if (parseInt(guess) === true) { alert('This is true'); } else { alert('This is false'); }

script.js 
var correctGuess = false;
var randomNumber = Math.floor(Math.random() * 6) +1;
var guess prompt('I am thinking of a number between 1 and 6. What is it?');
if (parseInt(guess) === true) {
    alert('This is true');
} else {
    alert('This is false');
}
index.html 
<!DOCTYPE HTML>
<html>
<head>
  <meta charset="UTF-8">
  <title>JavaScript Basics</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

1 Answer

Thomas Nilsen
Thomas Nilsen
14,957 Points
Thomas Nilsen
Thomas Nilsen
14,957 Points

A couple of things.

  • You're missing an equals
var guess prompt('I am thinking of a number between 1 and 6. What is it?');

should be

var guess = prompt('I am thinking of a number between 1 and 6. What is it?');

This check is problematic 

if (parseInt(guess) === true) {}

That will never be true because parseInt returns an int and it's being checked against a boolean using triple equals (===). When using triple equals, you saying that the value and type have to be equal.

You need to write

if (parseInt(guess) == randomNumber)

Notice the double equal (==), not triple.

Now, the number you entered through the prompt, is being checked against the randomly generated value.

here is a couple of examples to understand the difference between (==) and (===)

  • == only checks the value
  • === checks the type and value
console.log('1' == 1);      //true
console.log('1' === 1);     //false
console.log(1 == true);     //true
console.log(1 === true);    //false
console.log('' == false);   //true
console.log('' === false);  //false