FUNCTION:
isNaN
isNan(testvalue)
The isNaN function is used to determine if the argument, testvalue, is a NaN.
A NaN, which means "Not-a-Number", is classified as a primitive
value by the ECMA-262 standard and indicates that the specified value
is not a legal number.
The function returns true if the argument
is not a number and false if the argument is a number.
The classic example of a NaN is zero divided by zero, 0/0.
Code:
document.write(isNaN("Ima String"))
document.write(isNaN(0/0))
document.write(isNaN("348"))
document.write(isNaN(348))
Output:
true
true
false
false
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