6 个提高 React 代码质量的方法 - 让你的 React 代码更简洁

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2021-05-06 01:13

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简洁的代码具有更好的可读性,容易理解,且易于组织。本篇文章介绍 6 个在 React 中写简洁代码的技巧。

1. 条件渲染(一个条件时)

当你要根据条件来判断,以渲染不同的组件时,比如条件满足(为 true) 时,就渲染组件,否则不渲染(渲染空内容),这种情况下
不要用三元运算符,而是要用 
&& 这个操作符来处理,看下面的例子:不好的代码
import React, { useState } from 'react'
export const ConditionalRenderingWhenTrueBad = () => { const [showConditionalText, setShowConditionalText] = useState(false)
const handleClick = () => setShowConditionalText(showConditionalText => !showConditionalText)
return ( <div> <button onClick={handleClick}>Toggle the text</button> {showConditionalText ? <p>The condition must be true!</p> : null} </div> )}
改进后的代码
import React, { useState } from 'react'
export const ConditionalRenderingWhenTrueGood = () => { const [showConditionalText, setShowConditionalText] = useState(false)
const handleClick = () => setShowConditionalText(showConditionalText => !showConditionalText)
return ( <div> <button onClick={handleClick}>Toggle the text</button> {showConditionalText && <p>The condition must be true!</p>} </div> )}

2. 条件渲染(不同的条件时)

跟上面的情况有点像,也是根据条件来判断渲染的组件,只是条件不满足时不再渲染空内容,而是渲染别的组件内容。这个时候应该用三元运算符。不好的代码
import React, { useState } from 'react'
export const ConditionalRenderingBad = () => { const [showConditionOneText, setShowConditionOneText] = useState(false)
const handleClick = () => setShowConditionOneText(showConditionOneText => !showConditionOneText)
return ( <div> <button onClick={handleClick}>Toggle the text</button> {showConditionOneText && <p>The condition must be true!</p>} {!showConditionOneText && <p>The condition must be false!</p>} </div> )}
改进后的代码
import React, { useState } from 'react'
export const ConditionalRenderingGood = () => { const [showConditionOneText, setShowConditionOneText] = useState(false)
const handleClick = () => setShowConditionOneText(showConditionOneText => !showConditionOneText)
return ( <div> <button onClick={handleClick}>Toggle the text</button> {showConditionOneText ? ( <p>The condition must be true!</p> ) : ( <p>The condition must be false!</p> )} </div> )}

3. 布尔值属性

我们经常会传一个布尔类型的属性 (props) 给组件,类似 myTruthyProp={true} 这样的写法是没有必要的。

不好的代码

import React from 'react'
const HungryMessage = ({ isHungry }) => ( <span>{isHungry ? 'I am hungry' : 'I am full'}</span>)
export const BooleanPropBad = () => ( <div> <span> <b>This person is hungry: </b> </span> <HungryMessage isHungry={true} /> <br /> <span> <b>This person is full: </b> </span> <HungryMessage isHungry={false} /> </div>)

改进后的代码

import React from 'react'
const HungryMessage = ({ isHungry }) => ( <span>{isHungry ? 'I am hungry' : 'I am full'}</span>)
export const BooleanPropGood = () => ( <div> <span> <b>This person is hungry: </b> </span> <HungryMessage isHungry /> <br /> <span> <b>This person is full: </b> </span> <HungryMessage isHungry={false} /> </div>)
这样更简洁点,虽然只是一个小小技巧,但是可以从中看出你是不是一个有经验且优秀的程序员。

4. 字符串属性

跟上面的例子差不多,只是换成了字符串类型,这个时候,我们通常用双引号把字符串括起来,再加上花括号,如下面这样:不好的代码
import React from 'react'
const Greeting = ({ personName }) => <p>Hi, {personName}!</p>
export const StringPropValuesBad = () => ( <div> <Greeting personName={"John"} /> <Greeting personName={'Matt'} /> <Greeting personName={`Paul`} /> </div>)

改进后的代码

import React from 'react'
const Greeting = ({ personName }) => <p>Hi, {personName}!</p>
export const StringPropValuesGood = () => ( <div> <Greeting personName="John" /> <Greeting personName="Matt" /> <Greeting personName="Paul" /> </div>)

5. 事件绑定函数

我们经常会给一个组件绑定类似 onClick 或 onChange 这样的事件,比如我们可能会这样写:onChange={e => handleChange(e)},其实是没必要的,且看:

不好的代码

import React, { useState } from 'react'
export const UnnecessaryAnonymousFunctionsBad = () => { const [inputValue, setInputValue] = useState('')
const handleChange = e => { setInputValue(e.target.value) }
return ( <> <label htmlFor="name">Name: </label> <input id="name" value={inputValue} onChange={e => handleChange(e)} /> </> )}

改进后的代码

import React, { useState } from 'react'
export const UnnecessaryAnonymousFunctionsGood = () => { const [inputValue, setInputValue] = useState('')
const handleChange = e => { setInputValue(e.target.value) }
return ( <> <label htmlFor="name">Name: </label> <input id="name" value={inputValue} onChange={handleChange} /> </> )}

6. 组件属性

跟上面的例子差不多,我们也可以把组件作为属性传给别的组件,这个时候,支持使用把组件包成函数来传递,但没有接任何参数的时候,这种是没有必要的,且看:不好的代码
import React from 'react'
const CircleIcon = () => ( <svg height="100" width="100"> <circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" /> </svg>)
const ComponentThatAcceptsAnIcon = ({ IconComponent }) => ( <div> <p>Below is the icon component prop I was given:</p> <IconComponent /> </div>)
export const UnnecessaryAnonymousFunctionComponentsBad = () => ( <ComponentThatAcceptsAnIcon IconComponent={() => <CircleIcon />} />)

改进后的代码

import React from 'react'
const CircleIcon = () => ( <svg height="100" width="100"> <circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" /> </svg>)
const ComponentThatAcceptsAnIcon = ({ IconComponent }) => ( <div> <p>Below is the icon component prop I was given:</p> <IconComponent /> </div>)
export const UnnecessaryAnonymousFunctionComponentsGood = () => ( <ComponentThatAcceptsAnIcon IconComponent={CircleIcon} />)

总结

有时候写代码我们并没有注意到,多写一行,或多写内容有什么问题,但是有时候是没有必要的,我们尽量免这个,写出更好,更简洁的代码,这样别人能认为你是个有经验的程序员。


以上6个优化后的React 代码片段,如果您认为对您有帮助,请记得 点赞留言分享收藏 哦~~


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