Javascript循环只使用最后一个值 [英] Javascript loop only use the last value

问题描述

让stars = []; 
 //循环5次
 for（var i = 1; i< = 5; i ++）{
 //设置填充星的路径
 let path = require（ './star-filled.png'）; 
 if（i> this.state.cRating）{
 path = require（'./ star-unfilled.png'）; 
} 
 stars.push（（< TouchableHighlight onPress = {_ => this._RateApp（i）}>< Image style = {styles.image} source = {path} /> ;< / TouchableHighlight>））; 
} 

在

 this._RateApp（i）

函数中，我得到的所有图像的值都是6。请解释。



我尝试过：



关闭 - 处理javascript中的循环，只有最后一项受到影响？ - 堆栈溢出 [ ^ ]

解决方案

循环变量问题！ [ ^ ]

关闭循环变量在JavaScript中同样有害因为它在C＃中，修复起来比较麻烦 - 旧的新事物 [ ^ ]

闭包 - JavaScript | MDN [ ^

let stars = [];
    // Loop 5 times
    for (var i = 1; i <= 5; i++) {
      // set the path to filled stars
      let path = require('./star-filled.png');
      if (i > this.state.cRating) {
        path = require('./star-unfilled.png');
      }
      stars.push((<TouchableHighlight onPress={ _ => this._RateApp(i) }><Image style={styles.image} source={path} /></TouchableHighlight>));
    }

In

this._RateApp(i)

function, I am getting the value of i as 6 for all the images.Please explain.

What I have tried:

closures - dealing with loops in javascript, only last item gets affected? - Stack Overflow[^]

解决方案

Loop variable gotcha![^]
Closing over the loop variable is just as harmful in JavaScript as it is in C#, and more cumbersome to fix – The Old New Thing[^]
Closures - JavaScript | MDN[^]

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