单词首字母大写

// 普通low版
String.prototype.toJadenCase = function () {

    var arr = this.split(" ");

    var str = "";

    for (var i = 0; i < arr.length; i++) {
        var cap = arr[i].charAt(0).toLocaleUpperCase();
        
        arr[i] = arr[i].replace(/w{1}/, cap);

        if (!str) {
            str += arr[i];
        } else {
            str = str + " " + arr[i]
        }
    }
    return str;
};


var str = "How can mirrors be real if our eyes aren't real";

console.log(str.toJadenCase())

// 正则高大上版本
String.prototype.toJadenCase = function () {
  return this.replace(/(w)(w+)/g,function(a,b,c){
    return b.toUpperCase() + c;
  })
};

var str = "How can mirrors be real if our eyes aren't real";

console.log(str.toJadenCase())