React Conditional Rendering
In React, you can conditionally render components.
There are several ways to do this.
if Statement
We can use the if JavaScript operator to decide which component to render.
Example:
We'll use these two components:
function MissedGoal() {
return <h1>MISSED!</h1>;
}
function MadeGoal() {
return <h1>Goal!</h1>;
}
Example:
Now, we'll create another component that chooses which component to render based on a condition:
function Goal(props) {
const isGoal = props.isGoal;
if (isGoal) {
return <MadeGoal/>;
}
return <MissedGoal/>;
}
createRoot(document.getElementById('root')).render(
<Goal isGoal={false} />
);
Try changing the isGoal attribute to true:
Example:
createRoot(document.getElementById('root')).render(
<Goal isGoal={true} />
);
Logical && Operator
Another way to conditionally render a React component is by using the && operator.
In the example below, the heading will only be
rendered if the props.brand property is not empty:
Example:
The right side of && will only be rendered if the left side is true:
function Car(props) {
return (
<>
{props.brand && <h1>My car is a {props.brand}!</h1>}
</>
);
}
createRoot(document.getElementById('root')).render(
<Car brand="Ford" />
);
If props.brand evaluates to true,
the expression after && will render.
Try emptying the brand property:
Ternary Operator
Another way to conditionally render elements is by using a ternary operator.
condition ? true : false
We will go back to the goal example.
Example:
Return the MadeGoal component if
isGoal is true,
otherwise return the MissedGoal component:
function Goal(props) {
const isGoal = props.isGoal;
return (
<>
{ isGoal ? <MadeGoal/> : <MissedGoal/> }
</>
);
}
createRoot(document.getElementById('root')).render(
<Goal isGoal={false} />
);
To learn more, see the ternary operator section.
