javascript - 如何在函数之外使用变量？

Question

function ofInput() {
  const data = Array.from(
   this.children,
   tr => Array.from(tr.querySelectorAll('input'), input => input.value)
  );
}

document.querySelector('tbody').addEventListener('input', ofInput);

console.log(data);

该表在每个单元格中都有一个输入。将数据输出到输入时，数组中的数据应自动更改

标签： javascript

Answer 1

The data variable is inside the scope of the function ofInput. You need to declare the variable outside of the scope of function to access it. Try this out:

let data;
function ofInput() {
  data = Array.from(
   this.children,
   tr => Array.from(tr.querySelectorAll('input'), input => input.value)
  );
}

document.querySelector('tbody').addEventListener('input', ofInput);

if (data && typeof(data) === "array") console.log(data);
else console.log("Event did not occur");