问解释整整数而不是字符的字母数字排序算法- Javascript

EN

var arr = [
  "Grade 10 Applied",
  "Grade 10 Academic",
  "Grade 11",
  "Grade 11 Testy",
  "Grade 9",
  "Grade 8"
];

alert(arr.sort(function(a, b) {
  // split the strings into arrays of words
  var aParts = a.split(' ');
  var bParts = b.split(' ');
  // compare the corresponding words, if they are integers parseInt first
  for(var i=0; i < Math.min(aParts.length, bParts.length); i++) {
    var aPart = /\d+/.test(aParts[i]) ? parseInt(aParts[i]) : aParts[i];
    var bPart = /\d+/.test(bParts[i]) ? parseInt(bParts[i]) : bParts[i];
    if(aPart === bPart) { continue; }
    return aPart < bPart ? -1 : 1;
  }
  // fall back to using the array's length
  // ["dog", "cat"] < ["dog", "cat", "frog"]
  return aParts.length - bParts.length
}).join('\n'));