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How to test if a number or string is an integer in javascript

I want to test if a number or a string is an integer or not. Even for the number like 1.00 is actually an integer.

The javascript function to test it:

function IsInt(value)
{
     return (!(isNaN(value) || isNaN(parseInt(value))) && parseFloat(value) === parseInt(value));
}

In Javascript, isNaN method will return false for empty string, i.e., isNaN("") === false. However, parseInt("") will return NaN.

!(isNaN(value) || isNaN(parseInt(value)) will make sure the value is actually a number (it could be an integer or float). The next part parseFloat(value) === parseInt(value) will make sure the value is an integer type.

Here are some test results:

IsInt("") returns false
IsInt("123abc") returns false
IsInt("abc123") returns false
IsInt("1.0") returns true
IsInt(1) returns true
IsInt(1.2) returns false

Take a look at this live demo on jsbin.

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