Vue.js Essentials #04 Computed Properties

Computed properties are an essential feature of Vue.js that allows developers to perform complex calculations and logic in a more organized and efficient way. In this article, we’ll explore the basics of computed properties and how to use them in Vue.js applications.

What are Computed Properties?

In Vue.js, computed properties are functions that are defined on the Vue instance and are used to compute and return a value based on other data properties. Computed properties are reactive, which means that they will automatically update whenever their dependencies change.

Using Computed Properties

To define a computed property in a Vue component, you can use the `computed` property in the component’s options object. Inside the `computed` property, you can define a function that returns the computed value based on the data properties it depends on.

    
    new Vue({
      el: '#app',
      data: {
        firstName: 'John',
        lastName: 'Doe'
      },
      computed: {
        fullName: function() {
          return this.firstName + ' ' + this.lastName;
        }
      }
    });
    
  

In this example, we have defined a computed property called `fullName` that concatenates the `firstName` and `lastName` data properties. Whenever `firstName` or `lastName` changes, the `fullName` computed property will automatically update its value.

Benefits of Computed Properties

Computed properties offer several advantages over using methods or watching for changes in data properties. They are more efficient because they are cached and only re-evaluated when their dependencies change. This can lead to better performance, especially in complex applications with a large number of computed properties.

Computed properties also help to improve the organization and readability of the code by separating the logic for calculating derived values from the rest of the component’s methods. This makes the code easier to maintain and understand for other developers.

Conclusion

Computed properties are a powerful feature of Vue.js that enables developers to perform complex calculations and logic in a more organized and efficient way. By using computed properties, developers can create more maintainable and high-performing Vue.js applications.