javascript 类型错误：无法读取未定义的属性“0”
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时间：2020-10-27 05:36:05 来源:igfitidea点击:
TypeError: Cannot read property '0' of undefined
提问by fredley
When I call renderFrame, trying to access newLine[i]throws an error of
当我打电话时renderFrame，尝试访问newLine[i]会引发错误
Uncaught TypeError: Cannot read property '0' of undefined
Why is this? I've included the relevant code.
为什么是这样？我已经包含了相关的代码。
rows : ["-","-","-","-","-","-","-","-","-","-",],
generateLine : function(){
var result = new Array(10);
for(var i = 0; i < result.length; i++){
result[i] = " ";
}
},
renderFrame : function(){
var newLine = this.generateLine();
for(var i = 0; i < this.rows.length; i++){
console.log(newLine[i]);
}
},
回答by Halcyon
You forgot
你忘了
return result;
at the end of generateLine()
在......的最后 generateLine()
So newLineis now undefined. Hence Cannot read property '0' of undefined
所以newLine现在未定义。因此Cannot read property '0' of undefined
