javascript - 类型错误 : Cannot read property '0' of undefined

Question

当我调用 renderFrame 时，尝试访问 newLine[i] 会抛出错误

Uncaught TypeError: Cannot read property '0' of undefined

这是为什么？我已经包含了相关代码。

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]);
    }
},

Answer 1

你忘了

return result;

在 generateLine() 的末尾

所以 newLine 现在是未定义的。因此 Cannot read property '0' of undefined