How to Use If-else and Loop In JSX


By onjsdev

JSX is a syntax extension to JavaScript that allows us to write HTML-like code in our JavaScript files. One of the main benefits of JSX is that it allows us to write code that is both easier to read and write, while also making it more maintainable. In this article, we will discuss how to use conditional statements(if and if-else) and loops (javascript map) in JSX.

Conditional Statements in JSX

Conditional statements allow you to write code that only runs if a certain condition is met. In JSX, we can use the ternary operator or the if else statement to write conditional statements.

Ternary Operator

The ternary operator is a shorthand way of writing an if-else statement. It takes three operands: a condition, a value if the condition is true and a value if the condition is false. Here is an example of using the ternary operator in JSX:

const isTrue = true;

return (
  <div>
    {isTrue ? <p>This is true</p> : <p>This is false</p>}
  </div>
);

In the above code, we first declare a boolean variable called isTrue. We then use the ternary operator to conditionally render either a p element containing the text "This is true" or a p element containing the text "This is false".

If-Else Statement

The if-else statement is a more verbose way of writing a conditional statement. It takes a condition and runs one block of code if the condition is true and another block of code if the condition is false. Here is an example of using the if-else statement in JSX:

const isTrue = true;

if (isTrue) {
  return (
    <div>
      <p>This is true</p>
    </div>
  );
} else {
  return (
    <div>
      <p>This is false</p>
    </div>
  );
}

In the above code, we declare the same isTrue variable and use an if-else statement to conditionally render either a p element containing the text "This is true" or a p element containing the text "This is false".

Loops in JSX

Loops allow you to iterate over a collection of items and perform some action on each item. In JSX, we can use the map function to create a new array of JSX elements based on the original array.

Here is an example of using the map function to render a list of items in JSX:

const items = ["item 1", "item 2", "item 3"];

return (
  <ul>
    {items.map((item) => (
      <li>{item}</li>
    ))}
  </ul>
);

In the above code, we first declare an array of strings called items. We then use the map function to iterate over the items array and create a new array of li elements containing each item in the items array. We then render this array of li elements inside a ul element.

Conclusion

In this article, we have discussed how to use conditional statements and loops in JSX. Conditional statements allow you to write code that only runs if a certain condition is met, while loops allow you to iterate over a collection of items and perform some action on each item.

Thank you for reading.