Question

I have a input that i want to recive any number (dont matter if its negative, float, long) i code this to now allow null, undefined or empty values, but if I enter 0 it is read as empty

const inputElement = Number(document.getElementById("inputNumber").value);
  if (!inputElement) {
    window.alert("Insira um valor válido");
    return;
  }

i 已经尝试了这项工作,但又做了大量工作。

if (!inputElement && inputElement != 0){
  window.alert("Insira um valor válido");
  return;
 }

是否有任何人知道如何区分零与空洞或反之亦然?

Answer 1

Try this if(inputElement !== null)

这应当用于检查无效和未界定的(0个数字摘录)。

Bonus:

!a is true for numbers when a is undefined, null or equals to 0.
!a is true for strings when a is undefined, null or empty.

请让我知道这是否有助于你。

友情链接