检查数组是否包含数字（问题为0）

Question

I have an array of numbers. The array may contain a zero.

How can I check if the array contains a number or not? I am currently doing that:

if (Number(arr. value(pos)) != false)

This however, considers 0 as false too. So if a 0 is in the array, it will consider it as if the array was empty.

How can I overcome this?

Answer 1

Try this:

if (Number(arr. value(pos)) !== false)

!= does a "falsy" check. 0, undefined, false, null, '', and NaN are all falsy. Everything else is "truthy". If you want to test for false only (and not all other falsy statements) you have to use === or !== . Try to avoid != and == , because most if the time you actually mean !== and ===

Answer 2

koenp's answer is perfectly correct, but if (!isNaN(arr. value(pos))) might be preferable in this case. Also, it may be a notch faster. http://www.w3schools.com/jsref/jsref_isnan.asp

Answer 3

might be a solution. It checks whether the Number is bigger than Zero.