//javascr ipt 中的数组分割
var colors = ["red","green","blue"];
//alert(colors.toString());
alert(colors.join("|")); //返回结果是red|green|blue
var colors = ["red","green","blue",null];
alert(colors.join("|"));//red|green|blue|
//注意当数组里面有值是null或者是undefined的时候 返