CODEWITHSUNDEEP
javascriptreactjs
Terrence Wright
Terrence Wright

Reputation: 43

Uncaught ReferenceError: $ is not defined (react)?

Hello I am following a tutorial on learning React and right out of the gate am getting a undefined reference error. I am calling all the dependent libraries locally so I don't think it is a problem with hte libraries not fully loading. I am a newbie to React so I'm not sure what the issue is

I tried renaming the variables and looked through all the similar issues with reference errors posted here

<div id="entry-point"></div>

<script src="lib/react.js"></script>
<script src="lib/react-dom.js"></script>
<script src="lib/babel.js"></script>    

<script>
 console.log('notes')       
        let notes = [
          { id: 1, content: "Learn React" },
          { id: 2, content: "Get Lunch" },
          { id: 3, content: "Learn React Native" }
        ]

        class Note extends React.Component {
          render() {
            return React.createElement("li", {}, this.props.content)
          }
        }

        class NotesList extends React.Component {
          renderNote(note) {
            return React.createElement(Note, { key: note.id, content: note.content })
          }
          render() {
            let { notes } = this.props

            return React.createElement("ul", {}, notes.map(this.renderNote, this))
          }
        }

        class App extends React.Component {
          render() {
            let { notes } = notes

            return React.createElement(
              "section",
              {},
              React.createElement("h1", {}, "You have ", notes.length, " notes"),
              React.createElement(NotesList, { notes: notes })
            )
          }
        }

        ReactDOM.render(
          React.createElement(App, { notes: notes }),
          document.getElementById("entry-point")
        )
</script>

This is the error message I'm getting:

ReferenceError: Cannot access 'notes' before initialization
    at App.render (scratch.html:47)
    at h (react-dom.js:130)
    at beginWork (react-dom.js:134)
    at d (react-dom.js:158)
    at f (react-dom.js:159)
    at g (react-dom.js:159)
    at t (react-dom.js:167)
    at x (react-dom.js:166)
    at r (react-dom.js:164)
    at v (react-dom.js:163)

Upvotes: 1

Views: 8679

Answers (1)

dyouberg
dyouberg

Reputation: 2332

ReferenceError: Cannot access 'notes' before initialization at App.render (scratch.html:47)

So your compiler is telling you where your problem is, in this case line 47 inside your render function.

Then it is telling you that it cannot access before initialization. You are attempting to destructure with this syntax:

    let { notes } = notes

This is essentially saying "let notes = notes.notes;" Since notes is an array and doesn't have a property called notes - you are receiving an error. You already have notes defined in the scope, so try deleting that line and seeing what happens.

Upvotes: 3

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