為什么console出來是undefined呢？var ages = [3, 10, 18, 20];function zxc(data, dataArray){
dataArray.findIndex(function(element){ return element == data;
});
}console.log(zxc(18, ages)) //undefined這樣寫就沒問題
var ages = [3, 10, 18, 20]; var zxc = ages.findIndex(function(element){ return element == 18;
}); console.log(zxc) //2
關(guān)于js findIndex
蠱毒傳說
2019-01-30 15:59:32
