Altcademy - a Forbes magazine logo Best Coding Bootcamp 2023

How to turn an object into query string parameters in ReactJS

Introduction

ReactJS, an open-source JavaScript library, is widely revered for its flexibility and efficiency in building user interfaces (UIs). It is primarily used for single-page applications, allowing you to create reusable UI components. But as you're progressing in your ReactJS journey, you might stumble upon specific tasks that don't seem quite straightforward, such as turning an object into a query string parameter.

In this post, we'll unravel the mystery behind this task. We'll focus on the basic concepts first, then dive into the actual process with real-life code examples. Think of it as a cooking class where we'll turn raw ingredients (objects) into a ready-to-serve dish (query string parameters).

What are Objects in ReactJS?

Before we dive into the main topic, let's first understand what objects are in the context of ReactJS. You can think of an object like a bag that holds various items (properties). Each item has a label (key) so you can find it easily. For example, consider this object:

var student = {
  firstName: "John",
  lastName: "Doe",
  age: 20,
  grade: "Sophomore"
};

In this object named 'student', 'firstName', 'lastName', 'age', and 'grade' are the keys, and 'John', 'Doe', '20', and 'Sophomore' are their corresponding values.

What Are Query String Parameters?

Now let's understand what query string parameters are. Have you noticed the part of a URL that comes after a question mark '?'? That's a query string. Query strings allow us to pass data to the server in the form of key-value pairs.

For example, http://example.com/?firstName=John&lastName=Doe. Here, 'firstName' and 'lastName' are keys, and 'John' and 'Doe' are their respective values.

Why Turn an Object into Query String Parameters?

Imagine you're a photographer with countless photos. Without proper labeling (tags), finding a particular photo becomes a challenging task. Similarly, when we have a large number of data points, managing them without a proper system (like query parameters) is problematic. Converting objects to query string parameters makes it easy to pass data between pages or components and keep the UI updated.

The Process: Turning an Object into Query String Parameters

Now that you understand the 'why' let's delve into the 'how'. Here's the step-by-step process of converting an object into query string parameters in ReactJS.

Step 1: Create a Function

First, let's create a function that will do the heavy lifting for us. We'll call it objectToQueryString.

function objectToQueryString(obj) {
  // code goes here
}

Step 2: Use Object.keys Method

JavaScript's Object.keys method returns an array of a given object's property names, in the same order as we get with a normal loop. It's like getting the labels of all the items in our bag (object).

function objectToQueryString(obj) {
  const keys = Object.keys(obj);
  // more code goes here
}

Step 3: Use Array.map Method

Next, we'll use Array's map method. 'map' is like a factory assembly line. It takes an array, performs the same operation on each item, and returns a new array. We'll use 'map' to create a new array where each item is a string formatted as 'key=value'.

function objectToQueryString(obj) {
  const keys = Object.keys(obj);
  const keyValuePairs = keys.map(key => {
    return encodeURIComponent(key) + '=' + encodeURIComponent(obj[key]);
  });
  // more code goes here
}

Here, encodeURIComponent is a function that encodes a URI by replacing URL-unsafe characters with their percent-encoded UTF-8 equivalents. This ensures our URL is safe to use across the web.

Step 4: Use Array.join Method

Now, we have an array of 'key=value' strings. But we need to turn this array into a single string where each 'key=value' pair is separated by an ampersand '&'. For that, we'll use the 'join' method.

function objectToQueryString(obj) {
  const keys = Object.keys(obj);
  const keyValuePairs = keys.map(key => {
    return encodeURIComponent(key) + '=' + encodeURIComponent(obj[key]);
  });
  return keyValuePairs.join('&');
}

Step 5: Use the Function

Finally, let's use our function. Given an object, it will return a query string that we can append to our URL.

var student = {
  firstName: "John",
  lastName: "Doe",
  age: 20,
  grade: "Sophomore"
};

console.log(objectToQueryString(student)); // returns "firstName=John&lastName=Doe&age=20&grade=Sophomore"

Conclusion

And voila! We've successfully turned an object into query string parameters in ReactJS. It's like transforming a bag of labeled items (object) into a list of tagged photos (query string parameters), making it easier to find what you're looking for. This function is a handy tool to have in your ReactJS toolkit, especially when you're dealing with larger objects and need to pass data between UI components efficiently.

Remember, the key to mastering programming is understanding the basic concepts and knowing how and when to apply them. I hope this post helps you on your journey to become a proficient ReactJS developer. Keep practicing and happy coding!