javascript forEach范围(javascript forEach scope)

 我有以下代码 
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    tempGameState.forEach(function(row.bind(this), rowNum){
       ...
    }));
 
 当我在forEach循环之前放置我的console.log时： 
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    console.log(this.gameState)
    tempGameState.forEach(function(row.bind(this), rowNum){
       ...
    }));
 
 我把我的游戏状态作为输出 
 
 但当我把它放在forEach循环中时，如下所示： 
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    tempGameState.forEach(function(row.bind(this), rowNum){
        console.log(this.gameState)
       ...
    }));
 
 我得到了undefined 。 
 
 我知道这（通常）与范围有关，但是javascript文档没有说明正在创建的新范围或如何处理它。 

I have the following code
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    tempGameState.forEach(function(row.bind(this), rowNum){
       ...
    }));
 
when I put my console.log before the forEach loop like so:
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    console.log(this.gameState)
    tempGameState.forEach(function(row.bind(this), rowNum){
       ...
    }));
 
I get my game state as the output
 
but when I put it inside the forEach loop like so:
 
    var tempGameState = JSON.parse(JSON.stringify(this.gameState))
    tempGameState.forEach(function(row.bind(this), rowNum){
        console.log(this.gameState)
       ...
    }));
 
I get undefined.
 
I know this (ususally) has to do with scoping, but  the javascript docs don't say anything about a new scope being created or how to handle this.

原文：