parseInt() In JS?

Question

What is the use of parseInt() In JS?

Answer 1

parseInt()
extracts an integer/number from a given string.
var a=parseInt("23h");
a is now 23;
var a=parseInt("hallo");
a is now NaN since no int is available in "hallo";

Answer 2

Just to add to Brains , parseInt() will only be able to extract the integer from a given string if the string begins with an integer. Otherwise it still yields NaN, if the integer appears anywhere in the string but not the start.

var a = parseInt('hello5');
var a = parseInt('hel5lo');

// all the above results NaN

except if the integer begins as below:

var a = parseInt('5hello');
// a is now 5

Happy Coding!

Answer 3

Thanks Brains. I understand that.

Answer 4

Thank you so much Warith Vatanaplachaigoon your question helped me...

Answer 5

it is numbers without letters