javascript - 使用扩展等缩短 javascript 代码

Question

我有一个这样的函数:

initGrid: function(tableGridId, url) {
        var deviceTableGridId;
        if (typeof tableGridId != "undefined"){
            deviceTableGridId = tableGridId;
        } else {
            deviceTableGridId = gridId;
        }
        var getUrl;
        if (typeof url != "undefined"){
            getUrl = url;
        } else {
            getUrl = restUrl;
        } 
..
} 

如何才能将代码写得更短？我的意思是延长或等等？

Answer 1

    var deviceTableGridId = tableGridId || gridId,
        getUrl = url || restUrl;