How to implement array summation in react

How to implement array summation in react: 1. Create a code sample file; 2. Enter "import React,{useState,useEffect} from 'react';"; 3. Use controlled components and bind Set the onChange event; 4. Use the "function Sum(){...}" method to implement the sum.

The operating environment of this tutorial: windows10 system, react18 version, DELL G3 computer.

How to implement array summation in react?

React: Find the sum of all the numbers in the array

Requirement: Find the sum of all the numbers in the array

Analysis: Requirement Use controlled components and bind the onChange event (if you don’t bind, React will remind you...)

import React,{useState,useEffect} from 'react';
import ReactDOM from 'react-dom';
import './index.css';
function Sum(){
    const [val,setVal]=useState("1,2,3,4,5,6,7,8,9,10,11,12,13,14,15");
    const [sum,setSum]=useState('');
    const handleVal = function(e) {
        //let newVal=e.target.value;
        //newVal=newVal.replace(/[^(\d)|(,)]/,'');
        setVal(e.target.value.replace(/[^(\d)|(,)]/,''));
        //console.log(val);
    };
    const handleClick =function(){
        var sum=0;
        var inputs=val.split(',');
        for(var i in inputs){
            sum += parseInt(inputs[i]);
        }
        setSum(sum);
    }
    return(
        <div id="outer">
            <label>
                <input 
                type="text" 
                value={val}
                onChange={handleVal}
                />
                <span>输入数字求和，数字之间用半角","号分隔</span>
            </label>
            <p><button onClick={handleClick}>求和</button></p>
            <strong className="sum">{sum}</strong>
        </div>
    );
}
ReactDOM.render(
    <Sum/>,
    document.getElementById(&#39;root&#39;)
)

Recommended learning: "react video tutorial"

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