使用变量代替字符串

Question

I'm new to both JS and React and I'm working on a project for a bootcamp. I'm collaborating on a chat app and I wanted some insight on replacing strings with a variable to clean up the code. Here's what I'm working on:

import React from 'react';

const Form = React.createClass({

  submit(e) {
    e.preventDefault();
    this.props.messagesRef.push({
      text: this.refs.text.value,
      time: Date.now(),
      user: {
        displayName: this.props.user.displayName,
        photoURL: this.props.user.photoURL,
        uid: this.props.user.uid,
      },
    });
    this.refs.text.value = '';
  },

  render() {
    return (
      <form className="form" onSubmit={this.submit}>
    <input className="form-input" placeholder="Write     something…" ref="text"/>
        <button className="form-button">Send</button>
      </form>
    );
  }
});
export default Form;

I'd like to replace this.refs.text.value with a variable so I can clean up the code, but I'm not really sure how. Any help would be greatly appreciated

Answer 1

You can just use a variable to store the value and use it in place of this.refs.text.value :

submit(e) {
  e.preventDefault();
  var val = this.refs.text.value;

  this.props.messagesRef.push({
    text: val, //notice the use of val
    time: Date.now(),
    user: {
      displayName: this.props.user.displayName,
      photoURL: this.props.user.photoURL,
      uid: this.props.user.uid,
    },
  });
  this.refs.text.value = ''; //do not use val here!
},

This just uses a variable val in place of this.refs.text.value , although I would not recommend it because it doesn't necessarily make the code cleaner . Make sure not to change this.refs.text.value = ''; because if you do, you'll be reassigning the reference which is incorrect.