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javascript - Cannot access array values using a variable in javascript

问题描述

I am receiving an array from an HTML form. 

var parts=req.body.parts

Doing console.log(parts) returns an array:

['Part1','Part2']

However, for some reason the console.log(parts[i]) returns undefined.

However, if I change the value to console.log(parts[0]), I get [Part1] as my output. 

let loop= parts.length
for(i=0;i<loop;i++){
        console.log(i)
        console.log(parts[i])

    }

I cannot figure out why this is happening

标签： javascripthtml

解决方案

我在这里看到一些问题：

  1. 您正在使用变量parts和partNumber. 他们应该是一样的

  2. 您从未i在 for 循环中声明过，它应该如下所示：

const parts = req.body.parts;

for (let i = 0; i < parts.length; i++) {
    // do whatever

    console.log(i, parts[i]);

}

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