title: 如何形象地解释JavaScript中map、foreach、reduce间的区别？
topic: 前端开发
content: Array.prototype.map function fn var resultArray for var i 0，len this.length i < len i resultArrayi fn.applythis，thisi，i，this return resultArrayArray.prototype.forEach function fn for var i 0，len this.length i < len i fn.applythis，thisi，i，this Array.prototype.reduce function fn var formerResult this0 for