else if
statements to return slightly different UIs, you may repeat code which leaves room for error. Instead, you can use the &&
logical operator to perform conditional logic in a more concise way. This is possible because you want to check if a condition is true
, and if it is, return some markup. Here's an example:
{condition && <p>markup</p>}
If the condition
is true
, the markup will be returned. If the condition is false
, the operation will immediately return false
after evaluating the condition
and return nothing. You can include these statements directly in your JSX and string multiple conditions together by writing &&
after each one. This allows you to handle more complex conditional logic in your render()
method without repeating a lot of code.
h1
only renders if display
is true
, but use the &&
logical operator instead of an if/else
statement.
MyComponent
should exist and render.
testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); return mockedComponent.find('MyComponent').length; })(), 'MyComponent
should exist and render.');
- text: When display
is set to true
, a div
, button
, and h1
should render.
testString: '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(updated.find(''div'').length === 1 && updated.find(''div'').children().length === 2 && updated.find(''button'').length === 1 && updated.find(''h1'').length === 1, ''When display
is set to true
, a div
, button
, and h1
should render.''); }; '
- text: When display
is set to false
, only a div
and button
should render.
testString: '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(updated.find(''div'').length === 1 && updated.find(''div'').children().length === 1 && updated.find(''button'').length === 1 && updated.find(''h1'').length === 0, ''When display
is set to false
, only a div
and button
should render.''); }; '
- text: The render method should use the && logical operator to check the condition of this.state.display.
testString: getUserInput => assert(getUserInput('index').includes('&&'), 'The render method should use the && logical operator to check the condition of this.state.display.');
```