javascript - Accessing this.state value to other Class [React Native] - Stack Overflow

I just wanna ask how can i access this.state.sampleString from other class.. Here's my code

class MainClass extends Component {

  constructor(props){
      super(props)


      this.state = {
        sampleString: 'Test String'
      }

      this.getValue = this.getValue.bind(this);
    }


    getValue(){
        //console.log(this.state.sampleString);
        return this.state.sampleString
    }

}

=========

This is my function from My second class to get the value of "this.state. sampleString" from MainClass

function getValueFromMainClass() {

  var stringFromClassHeader = () => {HeaderWithBg.getValue()}

  console.log(stringFromClassHeader.sampleString);

}

Why it returns "undefined"?

Thanks alot. Im a new in react native.

I just wanna ask how can i access this.state.sampleString from other class.. Here's my code

class MainClass extends Component {

  constructor(props){
      super(props)


      this.state = {
        sampleString: 'Test String'
      }

      this.getValue = this.getValue.bind(this);
    }


    getValue(){
        //console.log(this.state.sampleString);
        return this.state.sampleString
    }

}

=========

This is my function from My second class to get the value of "this.state. sampleString" from MainClass

function getValueFromMainClass() {

  var stringFromClassHeader = () => {HeaderWithBg.getValue()}

  console.log(stringFromClassHeader.sampleString);

}

Why it returns "undefined"?

Thanks alot. Im a new in react native.

• javascript
• reactjs
• react-native

Share Improve this question Follow edited Mar 16, 2019 at 20:08 Vahid Boreiri 3,44811 gold badge2020 silver badges3535 bronze badges asked Sep 11, 2017 at 4:20 nico aurelio villanuevanico aurelio villanueva 11522 silver badges66 bronze badges

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1 Answer 1

Sorted by: Reset to default 4

You can send the this.state.sampleString as a prop to other ponents and use it there. A simple example of this is like below:

class MainClass extends Component {
  constructor(props){
      super(props)
      this.state = {
        sampleString: 'Test String'
      }

      this.getValue = this.getValue.bind(this);
    }

    getValue(){
        //console.log(this.state.sampleString);
        return this.state.sampleString
    }

    render(){
        return (
        <ChildClass sampleString={this.state.sampleString}/>


          )
        }
    }

class ChildClass extends Component {
    somefunction() {
        //console.log(this.props.sampleString);
        return this.props.sampleString
    }

    render(){
        return ...
    }
}