📜  html 输入最大字数 - Html 代码示例

📅  最后修改于: 2022-03-11 14:53:12.800000             🧑  作者: Mango

代码示例2
// Get all inputs that have a word limit
document.querySelectorAll('input[data-max-words]').forEach(input => {
  // Remember the word limit for the current input
  let maxWords = parseInt(input.getAttribute('data-max-words') || 0)
  // Add an eventlistener to test for key inputs
  input.addEventListener('keydown', e => {
    let target = e.currentTarget
    // Split the text in the input and get the current number of words
    let words = target.value.split(/\s+/).length
    // If the word count is > than the max amount and a space is pressed
    // Don't allow for the space to be inserted
    if (!target.getAttribute('data-announce'))
      // Note: this is a shorthand if statement
      // If the first two tests fail allow the key to be inserted
      // Otherwise we prevent the default from happening
      words >= maxWords && e.keyCode == 32 && e.preventDefault()
    else
      words >= maxWords && e.keyCode == 32 && (e.preventDefault() || alert('Word Limit Reached'))
  })
})