React JS Conditional Rendering

In this IT-dominated world, we are now forced to spend more of our time analyzing how to achieve better performance optimization. The programmer’s main objective is to utilize the right amount of time for optimizing the code as well as pushing reusable components as much as possible. This can be done through conditional rendering. Now you must be wondering what this term is and how you can implement it, right? Well, then you should continue reading as we are going to discuss what is React JS conditional rendering and the 5 ways how you can implement it in your code.

What is React JS Conditional Rendering?

While building an application through React Js or any other JavaScript library or framework, it is a common practice to either show or hide user interface components based on specific conditions. For instance, it could be a simple pop-up with the user clicking on a certain button or key, and then it hides when the button is not clicked. Another example is before signing or logging in we can see the “Sign up or Login ” button but once we have logged in that same button shows the “Log Out” button. Both of these processes are rendering user interface elements based on specific conditions hence called React JS conditional rendering.

What are the Prerequisites for React JS Conditional Rendering?

To learn about React JS conditional rendering and ways to implement them in your code, you are required to have a clear understanding of the following:

• Knowledge about JavaScript variables and functions
• Knowledge on how to import, export and render different React JS components
• Installation of Node.js locally

If you are unaware of these technologies do not need to worry because Codedamn is here for you! Ensure to check out Codedamn’s JavaScript and React JS courses in order to make React JS conditional rendering concepts easier to understand.

5 Practices for React JS Conditional Rendering

Now that you understand the need for conditional rendering, let us jump right to the different ways you can implement it. Below are the most useful ways to implement React JS conditional rendering:

1. If-else statements
2. Ternary Operation
3. Logical AND
4. Switch case operator
5. Enum Objects

Now let us discuss each of the methods in-depth:

1. If-else Statements

Conditional rendering in JavaScript and React JS is very similar. One can make use of JavaScript statements like if and else blocks to let React JS change the user interface element to match the condition. For instance, we use the if block with the condition and it returns the component which has to be rendered.

This React JS conditional rendering can cause wasted re-renders which do not affect small to medium applications. But the performance of large-scale projects will drop drastically as there will be hundreds or thousands of elements getting rendered causing a huge lag.

2. Ternary Operator

The conditional or the ternary operator is a JavaScript operator which takes three operands as its input and returns one output according to the condition. This operator is a shorthand implementation of the if-else block. The first part states the condition, the second part is the returned output if the condition is true and the last part is the return output if the condition is false.

3. Logical AND

The AND operator checks both the left and right expressions and then returns. If both the expressions are true, then it returns true or else false. We can use this AND operation to render JSX in React JS depending on certain conditions. The performance of this method for React JS conditional rendering is similar to the above two methods. But the AND operator along with JSX expressions is a better option as it forces you to rent the same structure while rendering and returning.

4. Switch Case Operator

The way we use switch case operators in JavaScript, the same way we can implement it in React JS as well. But you will require a self-invoking JavaScript function for this. Note that you will have to keep a default for the switch case operator as in React JS, every component has to return a null or a result. Switch case operator is one of the best ways to implement numerous React JS conditional rendering. However, using enums can be much more beneficial. Let’s see how.

5. Enum Object

Enums is a JavaScript object which can be used as a map for key and value pairs. We can use this object in React JS to create different components and pair them with components based on specific states. Now using a self-invoking function you can use enums to render components. Using enum is the best way to make use of multiple React JS conditional rendering as it is more readable and understandable in comparison to switching case operators.

Conclusion

There are many other ways to implement React JS conditional rendering in your web application like using high order components, element variables, or returning null. The above-mentioned methods are the easiest and most common practices used by developers. All these ways have their pros and cons. Hence according to your situation choose the method which fits you the best.