工作中的一些思路技巧

  function closest(el, selector) {
    const matchesSelector = el.matches || el.webkitMatchesSelector || el.mozMatchesSelector || el.msMatchesSelector
    let element = el
    while (element && element.removeChild) {
      if (matchesSelector.call(element, selector)) {
        return element
      }
      element = element.parentElement
    }
    return null
  }

  const delegate = document.querySelector('.js-delegate')
  delegate.addEventListener('click', (e) => {
    const target = closest(e.target, '.target1')
    if (!target) return
    // todo
  })

  delegate.addEventListener('click', (e) => {
    const target = closest(e.target, '.target2')
    if (!target) return
    // todo
  })

  delegate.addEventListener('click', (e) => {
    const target = closest(e.target, '.target3')
    if (!target) return
    // todo
  })

const DOMLIST = document.querySelectorAll('.item')
Array.prototype.forEach.call(DOMLIST, elm => {
  // todo
})

const DOMLIST = [].slice.call(document.querySelectorAll('.item'))
DOMLIST.forEach((item) => {
  // todo
})

const pixel = '200*50'
const [width, height] = pixel ? pixel.split('*') : [0, 0]