Before moving on to dynamic rendering techniques, there's one last way to use built-in JavaScript conditionals to render what you want: the <dfn>ternary operator</dfn>. The ternary operator is often utilized as a shortcut for <code>if/else</code> statements in JavaScript. They're not quite as robust as traditional <code>if/else</code> statements, but they are very popular among React developers. One reason for this is because of how JSX is compiled, <code>if/else</code> statements can't be inserted directly into JSX code. You might have noticed this a couple challenges ago — when an <code>if/else</code> statement was required, it was always <em>outside</em> the <code>return</code> statement. Ternary expressions can be an excellent alternative if you want to implement conditional logic within your JSX. Recall that a ternary operator has three parts, but you can combine several ternary expressions together. Here's the basic syntax:
The code editor has three constants defined within the <code>CheckUserAge</code> component's <code>render()</code> method. They are called <code>buttonOne</code>, <code>buttonTwo</code>, and <code>buttonThree</code>. Each of these is assigned a simple JSX expression representing a button element. First, initialize the state of <code>CheckUserAge</code> with <code>input</code> and <code>userAge</code> both set to values of an empty string.
Once the component is rendering information to the page, users should have a way to interact with it. Within the component's <code>return</code> statement, set up a ternary expression that implements the following logic: when the page first loads, render the submit button, <code>buttonOne</code>, to the page. Then, when a user enters their age and clicks the button, render a different button based on the age. If a user enters a number less than <code>18</code>, render <code>buttonThree</code>. If a user enters a number greater than or equal to <code>18</code>, render <code>buttonTwo</code>.
- text: The <code>CheckUserAge</code> component's state should be initialized with a property of <code>userAge</code> and a property of <code>input</code>, both set to a value of an empty string.
- text: When a number of less than 18 is entered into the <code>input</code> element and the <code>button</code> is clicked, the <code>button</code>'s inner text should read <code>You Shall Not Pass</code>.
- text: When a number greater than or equal to 18 is entered into the <code>input</code> element and the <code>button</code> is clicked, the <code>button</code>'s inner text should read <code>You May Enter</code>.
- text: Once a number has been submitted, and the value of the <code>input</code> is once again changed, the <code>button</code> should return to reading <code>Submit</code>.
