Uncaught TypeError Cannot read property setState of undefined

0 votes

I am getting the following error

Uncaught TypeError: Cannot read property 'setState' of undefined

even after binding delta in the constructor.

class Counter extends React.Component {
    constructor(props) {
        super(props);

        this.state = {
            count : 1
        };

        this.delta.bind(this);
    }

    delta() {
        this.setState({
            count : this.state.count++
        });
    }

    render() {
        return (
            <div>
                <h1>{this.state.count}</h1>
                <button onClick={this.delta}>+</button>
            </div>
        );
    }
}
Apr 27, 2020 in Java-Script by kartik
• 37,520 points
843 views

1 answer to this question.

0 votes

Hello kartik,

You dont have to bind anything, Just use Arrow functions like this:

class Counter extends React.Component {
    constructor(props) {
        super(props);

        this.state = {
            count: 1
        };

    }
    //ARROW FUNCTION
    delta = () => {
        this.setState({
            count: this.state.count++
        });
    }

    render() {
        return (
            <div>
                <h1>{this.state.count}</h1>
                <button onClick={this.delta}>+</button>
            </div>
        );
    }
}

Thank You!!

answered Apr 27, 2020 by Niroj
• 82,840 points

Related Questions In Java-Script

0 votes
0 answers

Uncaught TypeError: Cannot read property 'top' of undefined

I have two different kinds of sticky ...READ MORE

May 11, 2022 in Java-Script by Kichu
• 19,040 points
3,413 views
0 votes
0 answers

Cannot read property 'push' of undefined when combining arrays

When pushing an array's contents to another ...READ MORE

Nov 16, 2022 in Java-Script by Ashwini
• 5,430 points
579 views
0 votes
0 answers

Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>)

I was trying to change a string ...READ MORE

May 9, 2022 in Java-Script by Kichu
• 19,040 points
6,867 views
0 votes
0 answers

Sort array of objects by string property value

I have this array of JavaScript objects: var objs ...READ MORE

May 10, 2022 in Java-Script by Kichu
• 19,040 points
959 views
0 votes
1 answer

What are the vulnerability related to PHP Form?

Hii, The $_SERVER["PHP_SELF"] variable can be used by ...READ MORE

answered Feb 13, 2020 in PHP by Niroj
• 82,840 points
3,215 views
+1 vote
1 answer

How can we send message multiple time to a specific person or group in whatsapp using loop?

Hii @kartik,  This is simple task to send single ...READ MORE

answered Feb 28, 2020 in Java-Script by Niroj
• 82,840 points
18,730 views
0 votes
1 answer

What is meant by passing the variable by value and reference in PHP?

Hello, When the variable is passed as value ...READ MORE

answered Mar 27, 2020 in PHP by Niroj
• 82,840 points
3,283 views
0 votes
1 answer

Connection with MySQL server using PHP. How can we do that?

Hey @kartik, You have to provide MySQL hostname, ...READ MORE

answered Mar 27, 2020 in PHP by Niroj
• 82,840 points
1,322 views
0 votes
1 answer

Uncaught TypeError: Cannot read property 'indexOf' of undefined

Hello @kartik, First of all, you don't need ...READ MORE

answered Jun 2, 2020 in Java-Script by Niroj
• 82,840 points
19,588 views
0 votes
1 answer

Uncaught TypeError: Cannot use 'in' operator to search for '324'

Hello @kartik, You have a JSON string, not ...READ MORE

answered Jun 18, 2020 in Java-Script by Niroj
• 82,840 points
8,575 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP