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Tweaks to if-else tip
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@@ -7,25 +7,36 @@ prev: inline-styles.html
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next: self-closing-tag.html
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---
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`if-else` statements don't work inside JSX, since JSX is really just sugar for functions:
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`if-else` statements don't work inside JSX. This is because JSX is just syntactic sugar for function calls and object construction. Take this basic example:
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```js
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/** @jsx React.DOM */
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// this
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// This JSX:
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React.renderComponent(<div id="msg">Hello World!</div>, mountNode);
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// is the same as this
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// Is transformed to this JS:
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React.renderComponent(React.DOM.div({id:"msg"}, "Hello World!"), mountNode);
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```
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Which means `<div id={if (true){ 'msg' }}>Hello World!</div>` doesn't make sense, as (if it worked) it would be compiled down to something like this `React.DOM.div({id: if (true){ 'msg' }}, "Hello World!")`, which isn't valid JS.
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What you're searching for is ternary expression:
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This means that `if` statements don't fit in. Take this example:
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```js
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/** @jsx React.DOM */
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React.renderComponent(<div id={true ? 'msg' : ''}>Hello World!</div>, mountNode);
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// This JSX:
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<div id={if (condition) { 'msg' }}>Hello World!</div>
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// Is transformed to this JS:
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React.DOM.div({id: if (condition) { 'msg' }}, "Hello World!");
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```
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Try the [JSX compiler](/react/jsx-compiler.html).
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That's not valid JS. You probably want to make use of a ternary expression:
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```js
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/** @jsx React.DOM */
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React.renderComponent(<div id={condition ? 'msg' : ''}>Hello World!</div>, mountNode);
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```
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Try using it today with the [JSX compiler](/react/jsx-compiler.html).
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