TypeError：this.props.function不是函数

Question

First of all, I would like to say that I know there are many questions regarding this topic. I read through most of them and I double and triple checked my code but I can't seem to get it to work.

I have the following child component, which contains an image, which you can change by clicking on said image (you can iterate through an array of 5 images).

export default class Images extends React.Component {
    constructor(props) {
        super(props);
        this.changeIcon = this.changeIcon.bind(this);
        this.state = {pointer: this.props.id-1, imgs: props.imgs };
    }

    changeIcon () {
        const {length} = this.state.imgs;
        const {pointer } = this.state;
        const newPointer = pointer === length - 1 ? 0 : pointer+1;
        this.setState({ pointer: newPointer });
        this.props.onChangeIcon("I work");
    }

    render() {
        const isclicked = this.props.clicked;
        const { pointer, imgs } = this.state;
        return(
            <img src={imgs[pointer]} onClick={this.changeIcon}/>
        );
    }
}

This is the parent component:

import Images from "./images";

class Displayer extends React.Component {
    constructor(props) {
        super(props);
        this.changeIcons = this.changeIcons.bind(this);
        this.state = {
            imgs = [link1, link2, link3, link4, link5]
        }
    }
    changeIcons(word) {
        console.log(word);
    }

    render () {
        return (
            <div>
                <Images onChangeIcon={this.changeIcons} imgs={this.state.imgs}/>
            </div>
        )
    }

}

The weird thing is, that it works perfectly fine with another function inside the same child component. I used the same structure and I also double-checked for any spelling mistakes, but nothing helped.

I still receive the same error message TypeError: this.props.changeIcon is not a function . Am I missing something? Can anyone spot a mistake?

Edit: the id-prop is added at another point. In order so keep it simple I did not include that.

Answer 1

changeIcons doesn't belong to props but just a method of your component

Instead of this:

<Images onChangeIcon={this.props.changeIcons}

Try this:

<Images onChangeIcon={this.changeIcons}

UPDATE:

Try to use arrow function in the callback to see where the problem is:

return (
    <img src={imgs[pointer]} onClick={() => this.changeIcon() }/>
);

Or just turn changeIcon into arrow function:

changeIcon = () => {
    const {length} = this.state.imgs;
    const {pointer } = this.state;
    const newPointer = pointer === length - 1 ? 0 : pointer+1;
    this.setState({ pointer: newPointer });
    this.props.onChangeIcon("I work");
}

render() {
    const isclicked = this.props.clicked;
    const { pointer, imgs } = this.state;
    return(
        <img src={imgs[pointer]} onClick={this.changeIcon}/>
    );
}

Answer 2

First thing you have done mistake in constructor function. pass imgs and ids also as you are using in child component. Do it like this

import Images from "./images";

class Displayer extends React.Component {
    changeIcons = (word) => {
        console.log(word);
    }
    state = {
     imgs : ["img1","img2", "img3"],
     id: 0,
    }
//Here i dont know how you are getting img urls array.Please add your code accordingly
    render () {
        return (
            <div>
                <Images imgs={this.state.imgs} onChangeIcon={this.changeIcons} />
            </div>
        )
    }

}

And thats it, now it should work.