简体   繁体   中英

How can I pass the index from javascript map function to the onclick function?

I have an array of data that I'm iterating through, In the javascript map() function call I'm using the second argument that map() takes, 'index'. How would I pass index to the onClick event? I tried adding index to the list of arguments for onClick but all I can access are the events. Is there anyway I can pass the index through?

I'd like to be able to execute the commented out line 'handleImageClick(productObjects[index])'. I need to let the parent component know which productObject was clicked on by the user.

export default function SideProducts(props) {
    
const { productObjects, handleImageClick } = props;


const onClick = (e) => {
    e.persist()
    console.log(e)
    //handleImageClick(productObjects[index])
}

console.log(productObjects)
    return (
        <Wrapper>
            {productObjects.map((productObject,index) => (
                <ImageWrapper key={index} src={productObject.image} onClick={(e) => onClick(e)}>
                    
                </ImageWrapper>
            ))}
        </Wrapper>
    )
}

I am doing this without testing, but you should be able to just pass the index like this.

const onClick = (e, index) => {
    e.persist()
    console.log(e)
    //handleImageClick(productObjects[index])
}

console.log(productObjects)
    return (
        <Wrapper>
            {productObjects.map((productObject,index) => (
                <ImageWrapper key={index} src={productObject.image} onClick={(e) => onClick(e, index)}>
                    
                </ImageWrapper>
            ))}
        </Wrapper>
    )
}

This way. please go through this blog to learn more about passing arguments with onClick

export default function SideProducts(props) {
    
const { productObjects, handleImageClick } = props;


const onClick = (e, index) => {
    e.persist()
    console.log(e, index)
    //handleImageClick(productObjects[index])
}

console.log(productObjects)
    return (
        <Wrapper>
            {productObjects.map((productObject,index) => (
                <ImageWrapper key={index} src={productObject.image} onClick={(e) => onClick(e, index)}>
                    
                </ImageWrapper>
            ))}
        </Wrapper>
    )
}
  1. First you need to pass the index as argument. onClick={(e) => onClick(e, index)}

  2. Then receive that index as functional parameter.

const onClick = (e, index) => {
    e.persist()
    console.log(e, index)
    //handleImageClick(productObjects[index])
}

Just add it as a parameter to yow onClick

        <ImageWrapper key={index} src={productObject.image} onClick={(e) => onClick(e,productObject.addThePropHere)}>
                    
                </ImageWrapper>

Then in your function just add it as well

const onClick = (e,prop)=> ….code

You can use a higher-order function here to pass params as you want:

const handleWithIndex= index => {
    return (event) => {
         e.persist()
         //handleImageClick(productObjects[index])
    }
}

return (
        <Wrapper>
            {productObjects.map((productObject,index) => (
                <ImageWrapper key={index} src={productObject.image} onClick={handleWithIndex(index)}>
                    
                </ImageWrapper>
            ))}
        </Wrapper>
    )
}

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM