Object.entries pulls out an array of arrays based on the key/value pairs of the original object: [['a', 1],[' ... ... <看更多>

後來ES5 新增的Object.keys() 解決了非own property 的問題， ... JavaScript 之旅(4)：Object.keys() & Object.values() ... forEach() 來迭代： ... ... <看更多>

This tutorial introduces you to the JavaScript Map object and shows you how ... forEach(callback[, thisArg]) – invokes a callback for each key-value pair in ... ... <看更多>

Up vote 5 Down vote. You cannot iterate over normal javascript simple array, it needs to be array of object. ... You can't use index as a value for key. ... <看更多>

JavaScript forEach Object, Array and String. ... throw new TypeError("forEach: callBack should be function, ... console.log(key + ": " + value);. ... <看更多>