手机号自动加空格

function Mobile(str) {
  var value = str.replace(/\s*/g, "")
  var result = []
  for (var i = 0; i < value.length; i++) {
    if (i == 3 || i == 7) {
      result.push(" " + value.charAt(i));
    } else {
      result.push(value.charAt(i));
    }
  }
  return value = result.join('')
  
}