getting error when exporting variable in reactjs

问题

hello i have this component in react js :

import React from 'react';
import './Questions.css';

const Questions = (props) => {
    

    let questions = Object.keys(props.slices).map((questionKey, i) => (
        <li key={i}>
            <p>{props.slices[questionKey].question}</p>
            <div className="Answer">
                <input
                onChange={props.selectScore(questionKey)} 
                type="range" 
                min="1" 
                max="10" 
                value={props.slices[questionKey].transform === '1' ? '10' : props.slices[questionKey].transform.replace('0.','')} 
                className="rangeInput"
                style={{background: props.slices[questionKey].fill}} />
                <span className="Score" style={{backgroundColor: props.slices[questionKey].fill}}>
                    <div className="leftArrow" style={{borderRight: '5px solid ' + props.slices[questionKey].fill}}></div>
                   <span className="Score" style={{backgroundColor: props.slices[questionKey].fill}}>
                    {/* <div className="leftArrow" style={{borderRight: '5px solid ' + props.slices[questionKey].fill}}></div> */}
                    {props.slices[questionKey].transform === '1' ? '10' : props.slices[questionKey].transform.replace('0.','')}
                  </span>
                </span>

 
            </div>

        </li>
        
    ));
    
    return (
        <>
           
            My variable = {props.slices[2].transform === '1' ? '10' : props.slices[2].transform.replace('0.','')}

            {questions}
        </>
    );

    
    
}


export default Questions;

i need to export this line which is in the return function: {props.slices[2].transform === '1' ? '10' : props.slices[2].transform.replace('0.','')} as a variable to use it in another component .
so i did this :

export const V = (value) => (
  value === {props.slices[2].transform === '1' ? '10' : props.slices[2].transform.replace('0.','')}
)

but i'm getting this error : Unexpected token, expected "," (47:20)
could someone help me to export the variable . thank you in advance

回答1:

As you wrote

i need to export this line which is in the return function: {props.slices[2].transform === '1' ? '10' : props.slices[2].transform.replace('0.','')} as a variable to use it in another component

I assume, you don't want to render anything in this component rather just want to return some computed values? Right? If Yes, then you shoould simple return the values like this.

import React from 'react';
import './Questions.css';

const Questions = (props) => {
    
    // better to use const instead of let, if you don't need to modify a variable...
    const questions = Object.keys(props.slices).map((questionKey, i) => (
        <li key={i}>
            <p>{props.slices[questionKey].question}</p>
            <div className="Answer">
                <input
                onChange={props.selectScore(questionKey)} 
                type="range" 
                min="1" 
                max="10" 
                value={props.slices[questionKey].transform === '1' ? '10' : props.slices[questionKey].transform.replace('0.','')} 
                className="rangeInput"
                style={{background: props.slices[questionKey].fill}} />
                <span className="Score" style={{backgroundColor: props.slices[questionKey].fill}}>
                    <div className="leftArrow" style={{borderRight: '5px solid ' + props.slices[questionKey].fill}}></div>
                   <span className="Score" style={{backgroundColor: props.slices[questionKey].fill}}>
                    {/* <div className="leftArrow" style={{borderRight: '5px solid ' + props.slices[questionKey].fill}}></div> */}
                    {props.slices[questionKey].transform === '1' ? '10' : props.slices[questionKey].transform.replace('0.','')}
                  </span>
                </span>

 
            </div>

        </li>
        
    ));
    
    const myVar = props.slices[2].transform === '1' ? '10' : props.slices[2].transform.replace('0.','');

    return {myVar,questions};    
    
}


export default Questions;

And if you return the values like this return (<> ... some JSX ... </>); then it will be some rendered JSX, which I think you can't simple export as variable to be used by another component.

Update

To use myVar in another component do this

import Questions from 'questions-file-name';

const selectScore= (key)=>{
// do something with score using key
}

const {myVar,questions} = Questions(slices,selectScore); 

来源：https://stackoverflow.com/questions/64909431/getting-error-when-exporting-variable-in-reactjs