CODEWITHSUNDEEP
javascriptcompare
meJustAndrew
meJustAndrew

Reputation: 6613

How does comparison between a string a an integer work in javascript?

I just found a piece of code in which it is compared a string to an integer like this :

var result = "text" > 127;

and the result of this line of code is false. I have also tried to change it to equals or less than, and the result was still false:

var result = "text" === 127;
var result = "text" < 127;

What is the meaning to compare a string and a number like this if it always return false, or are there any cases when this will be true?

Upvotes: 1

Views: 107

Answers (1)

Sergio Cabral
Sergio Cabral

Reputation: 6968

When you compare string with number the string is converted to number, but in this case, "text", the result is NaN (translate is Not a Number). Always result false, because an NaN is not a number to compare.

Verify with this:

var n1 = Number("text");
console.log(n1); //show NaN

So...

var result = "text" > 127;

Is equals

var result = NaN > 127; //result false always with any compare

But, if the text is a number can be converted

var result = "00999" > 127; //result true, because Number("00999") == 999

Upvotes: 1

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