這是Mozilla的代碼在Mozilla的Array.prototype.indexOf問題上的代碼在Mozilla的Array.prototype.indexOf
if (!Array.prototype.indexOf)
{
Array.prototype.indexOf = function(elt)
{
var len = this.length >>> 0; // What does ">>>" do?
var from = Number(arguments[1]) || 0;
from = (from < 0) ? Math.ceil(from): Math.floor(from);
if (from < 0)from += len;
for (; from < len; from++)
{
if (from in this && this[from] === elt)return from;
}
return -1;
};
}
我有些不明白的語法。
「>>>」在上面的代碼中做了什麼?
精確複製:http://stackoverflow.com/questions/1385491/javascript-why-use-around-arguments-and-why-use-when-extracting-the – 2009-09-25 02:09:35