css-in-js example

styles-in-js.js

class Post extends React.Component {
  
  onSponsorPost(){
    if(this.props.post.type === 'sponsored'){
      return '#F9BF3B' //gold color
    }    
  }
  
  render(){
      // web
      <div>
        <div style={[styles.thumbnail, {backgroundColor: this.onSponsorPost()}]}>
      </div>
    
    // react native
    
    <View>
      <View style={[styles.thumbnail, {backgroundColor: this.onSponsorPost()}]}>
    </View>
  }

}

//next.js web framework 

const styles = {
  thumbnail: {
    margin: 5,
    padding: 5,
    backgroundColor: '#91969A', //grey
    borderRadius: 3,
    minWidth: 66
  }
}

// react native
const styles = StyleSheet.create({
   thumbnail: {
    margin: 5,
    padding: 5,
    backgroundColor: '#91969A', //grey
    borderRadius: 3,
    minWidth: 66
  }
})