JavaScript函数参数默认值
// Combiner of passed arguments and defaults (usable with any function) Object.prototype.combine = function(_args){ for(var i in this) { if(typeof _args[i] == "undefined") { _args[i] = this[i]; } } }; // Specific example function with defaults function feedTheCat(args){ var defaults = { 'morning' : "nothing", 'noon' : "pork", 'nite' : "mouse" }; defaults.combine(args); } // USAGE: only passing 2 of 3 arguments feedTheCat({ 'morning': "milk", 'nite': "kitekat" }); // Values would be: milk | pork | kitekat