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JavaScript Introducing the Practice

Emanuel Rouse
Emanuel Rouse
1,985 Points
Posted by Emanuel Rouse
Emanuel Rouse
1,985 Points

My conditional statement isn't running due to the isNaN method. Please help.

My conditional statement follows what Dave shows.

if (isNaN(num2)){
  alert('Cannot divide by 0. Please reload and try again.');
}

However the code block isn't running. I've managed to get it to work by doing this:

if (isNaN(num2 / 0) {
 alert('Cannot divide by 0. Please reload and try again.');
}

But I'm not sure why this works. Can someone explain this to me? I've watched a few videos on isNaN and also checked the MDN docs on it however it's still going over my head.

2 Answers

Bartlomiej Pajak
Bartlomiej Pajak
5,062 Points
Bartlomiej Pajak
Bartlomiej Pajak
5,062 Points

It should be more like this:

if ( num2 === 0 ) {
  alert("The second number is 0. You can't divide by zero. Reload and try again.");
}

if ( isNaN(num1) || isNaN(num2) ) {
  alert("At least one of the values you typed is not a number. Reload and try again.");
}
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,967 Points
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,967 Points

Based on your alert it looks like you are testing num2 = 0. If that is the case then your conditional statement is false because 0 is a number. If you try a word on the other hand like 'beaver' or leave it blank then the statement is true and the alert is displayed.