--- id: 5a24c314108439a4d4036184 title: Render with an If-Else Condition challengeType: 6 forumTopicId: 301410 dashedName: render-with-an-if-else-condition --- # --description-- Another application of using JavaScript to control your rendered view is to tie the elements that are rendered to a condition. When the condition is true, one view renders. When it's false, it's a different view. You can do this with a standard `if/else` statement in the `render()` method of a React component. # --instructions-- MyComponent contains a `boolean` in its state which tracks whether you want to display some element in the UI or not. The `button` toggles the state of this value. Currently, it renders the same UI every time. Rewrite the `render()` method with an `if/else` statement so that if `display` is `true`, you return the current markup. Otherwise, return the markup without the `h1` element. **Note:** You must write an `if/else` to pass the tests. Use of the ternary operator will not pass here. # --hints-- `MyComponent` should exist and render. ```js assert( (function () { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); return mockedComponent.find('MyComponent').length === 1; })() ); ``` When `display` is set to `true`, a `div`, `button`, and `h1` should render. ```js async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); const state_1 = () => { mockedComponent.setState({ display: true }); return waitForIt(() => mockedComponent); }; const updated = await state_1(); assert( mockedComponent.find('div').length === 1 && mockedComponent.find('div').children().length === 2 && mockedComponent.find('button').length === 1 && mockedComponent.find('h1').length === 1 ); }; ``` When `display` is set to `false`, only a `div` and `button` should render. ```js async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); const state_1 = () => { mockedComponent.setState({ display: false }); return waitForIt(() => mockedComponent); }; const updated = await state_1(); assert( mockedComponent.find('div').length === 1 && mockedComponent.find('div').children().length === 1 && mockedComponent.find('button').length === 1 && mockedComponent.find('h1').length === 0 ); }; ``` The render method should use an `if/else` statement to check the condition of `this.state.display`. ```js (getUserInput) => assert( getUserInput('index').includes('if') && getUserInput('index').includes('else') ); ``` # --seed-- ## --after-user-code-- ```jsx ReactDOM.render(, document.getElementById('root')) ``` ## --seed-contents-- ```jsx class MyComponent extends React.Component { constructor(props) { super(props); this.state = { display: true } this.toggleDisplay = this.toggleDisplay.bind(this); } toggleDisplay() { this.setState((state) => ({ display: !state.display })); } render() { // Change code below this line return (

Displayed!

); } }; ``` # --solutions-- ```jsx class MyComponent extends React.Component { constructor(props) { super(props); this.state = { display: true } this.toggleDisplay = this.toggleDisplay.bind(this); } toggleDisplay() { this.setState((state) => ({ display: !state.display })); } render() { // Change code below this line if (this.state.display) { return (

Displayed!

); } else { return (
); } } }; ```