Event.target.value 未返回预期值

Question

My code is working but I'm curious to know why... I think it has something to do with the reference in memory but I can't find a direct answer.

Some context, I had to modify the value of a phone field on each input to trim the spaces between the strings.

const phoneInput = document.querySelector('.phoneInput')
phoneInput.addEventListener('input', function(event) {
  const trimedValue = event.target.value.replace(/\D/g, '')
  return event.target.value = trimedValue
})

This is done and works.

My question is, why isn't it working when I write this ?

const phoneInput = document.querySelector('.phoneInput')
phoneInput.addEventListener('input', function(event) {
  return event.target.value.replace(/\D/g, '')
})

Answer 1

这仅仅是因为您在第一个块中为 event.target.value 分配了一些值，但在第二个块中，您只是从 event.target.value 获取值并对其执行一些操作。