6.对象

var fruit = new Array("苹果", "梨子", "橘子");
var i;

for (i=0; i < fruit.length; i++) {
    document.write("fruit [", i, "] = ", fruit[i], "<br>")
}

</Script>

var fruit = new Array("苹果", "梨子", "橘子");

document.write("<LI>", fruit.join());
document.write("<LI>", fruit.join("、"));
document.write("<LI>", fruit.toString());
document.write("<LI>", fruit.reverse().join());
document.write("<LI>", fruit.valueOf());

</Script>

var fruit = new Array(3);
fruit[0] = new Array("苹果", 2);
fruit[1] = new Array("梨子", 4);
fruit[2] = new Array("橘子", 2);

for (i=0; i < fruit.length; i++) {
  for (j=0; j < fruit[0].length; j++) {
    document.write("fruit [", i, "][", j, "] = ", fruit[i][j],"<br>");
  }
  document.write("<br>");
}

</Script>

</Script>

document.write(str, " 有 ", str.length, " 个字<BR>");
document.write(str.fontcolor("green"), " 不是 ");
document.write(str.substr(0,4).fontcolor("red"));
document.write(" 也不是 ", str.replace("Java", "VB"));

</Script>

document.write(usr.toUpperCase().fontsize(7), "<BR>");
document.write("你的电子信箱是", str);

</Script>

function isEmail(){
  var str = document.form1.add.value;
  if (str.indexOf("@") == -1)
    alert("请填写正确的EMail地址");
  else
    alert("OK!");
}

</Script>

<FORM name="form1">
请输入你的 EMail 地址：
<INPUT TYPE="text" name="add">
<INPUT TYPE="button" value="开始检查" onClick="isEmail()">
</FORM>

x = new Boolean();
y = new Boolean(true);
z = new Boolean(0);

document.write(x, "<br>");
document.write(y, "<br>");
document.write(z, "<br>");

</Script>

with (document) {
    write("<LI>2 的平方根值是 ", Math.sqrt(2));
    write("<LI>2 ³ = ", Math.pow(2,3));
    write("<LI>最接近 3.14 的整数是 ", Math.round(3.14));
}

</Script>

var now = new Date();
var firstDay = new Date("Nov 10, 1999");
var duration = now - firstDay;
var msPerDay = 24 * 60 * 60 * 1000; //换算成毫秒
days = Math.round(duration/msPerDay);

document.write("本网站已经开幕" + days + "天了");

</Script>

例3：
<Script>

var promote = new Array(3);
promote[0] = "拍卖区又有新货到了，赶快来捡便宜啊......"
promote[1] = "成为会员，马上享受八折优惠，还可以参加抽奖！";
promote[2] = "庆祝访问人数突破十万人次，填问卷就送大奖，快来啊！";

index = Math.floor(Math.random() * promote.length);
document.write(promote[index]);

</Script>

• 自定义对象；
  • 构造函数定义对象类型；
  • 建立对象实例。
• 例：
  <Script>

  function member(name, sex) {
      this.name = name;
      this.sex = sex;
  }
  
  var papa = new member("杨宏文", "男生");
  var mama = new member("黄雅玲", "女生");
  var doggy = new member("奇　奇", "宠物狗");
  
  document.write(papa.name);
  document.write("是", papa.sex);

  </Script>

• 动态的定义对象属性；
• 例：
  为指定的对象实例定义属性：papa.hobby="看电视";
  为对象定义属性：member.prototype.hobby=null;
  　　　　　　　　papa.hobby="上网";
  　　　　　　　　mama.hobby="逛街";
  　　　　　　　　doggy.hobby="啃骨头";
  
  
• 定义对象的方法；
  • 构造函数定义对象方法名；
  • 建立方法的描述函数。
• 例：
  <Script>

  function member(name, sex) {
    this.name = name;
    this.sex = sex;
    this.display = display;
  }
  
  function display() {
    var str = this.name + "是" + this.sex;
    document.write("<LI>" + str);
  }
  
  var papa = new member("杨宏文", "男生");
  var mama = new member("黄雅玲", "女生");
  var doggy = new member("奇　奇", "宠物狗");

  papa.display();
  mama.display();
  doggy.display();
  
  </Script>

String.prototype.replaceAll = strReplace;
function strReplace(findText, replaceText) {
  var str = new String(this);
  while (str.indexOf(findText)!=-1) {
    str = str.replace(findText, replaceText);
  }
  return str;
}

myStr = "告诉你 － 如果你正在寻找一本能帮助你彻底研究" +
"JavaScript的书籍，请你一定要认明碁峰的" +
"JavaScript教学范本，让你事半功倍，功力大增。";
document.write("<LI>原稿是：<BLOCKQUOTE>" + myStr +"</BLOCKQUOTE>");
document.write("<LI>利用Replace()将「你」改成「您」："
+"<BLOCKQUOTE>" + myStr.replace('你','您') +"</BLOCKQUOTE>");
document.write("<LI>利用自定义的字符串方法 - 全部取代"
+"<BLOCKQUOTE>" + myStr.replaceAll('你','您') +"</BLOCKQUOTE>");

</Script>