jQuery jQuery.map() Method

Posted in jQuery Tutorial

Updated on May 13, 2024

By Mari Selvan

👁️ 15 - Views

⏳ 4 mins

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Photo Credit to CodeToFun

🙋 Introduction

The jQuery library offers a plethora of methods to simplify DOM manipulation and traversal. One such method is jQuery.map(), which provides a convenient way to transform arrays and objects. By understanding and mastering the jQuery.map() method, you can efficiently manipulate data structures within your web applications.

In this comprehensive guide, we'll delve into the functionality and usage of the jQuery.map() method, accompanied by clear examples to illustrate its versatility.

🧠 Understanding jQuery.map() Method

The jQuery.map() method serves as a utility for transforming arrays and objects by applying a function to each element. It allows you to iterate over collections and modify their contents based on custom logic.

💡 Syntax

The syntax for the jQuery.map() method is straightforward:

syntax.js

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jQuery.map(array, callback(elementOfArray, indexInArray))
jQuery.map(object, callback(value, indexOrKey))

Parameters:

array: An array or array-like object to iterate over.
object: An object or array-like object to iterate over.
callback: A function to execute on each element of the array or object.

📝 Example

Mapping Array Elements:

Suppose you have an array of numbers and you want to double each value. You can achieve this using the jQuery.map() method as follows:
example.js
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```
var numbers = [1, 2, 3, 4, 5];
var doubledNumbers = jQuery.map(numbers, function(value) {
  return value * 2;
});
console.log(doubledNumbers); // Output: [2, 4, 6, 8, 10]
```

Mapping Object Properties:

Similarly, you can iterate over object properties and modify their values. Let's convert an object of temperatures from Celsius to Fahrenheit:

example.js

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var temperatures = { "London": 20, "New York": 15, "Tokyo": 25 };
var fahrenheitTemperatures = jQuery.map(temperatures, function(value, key) {
    return key + ": " + ((value * 9/5) + 32) + "°F";
});
console.log(fahrenheitTemperatures); // Output: ["London: 68°F", "New York: 59°F", "Tokyo: 77°F"]

Filtering Array Elements:

You can also use jQuery.map() to filter array elements based on certain conditions. Here's an example where we extract even numbers from an array:
example.js
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```
var numbers = [1, 2, 3, 4, 5];
var evenNumbers = jQuery.map(numbers, function(value) {
    return value % 2 === 0 ? value : null;
});
console.log(evenNumbers); // Output: [2, 4]
```

🎉 Conclusion

The jQuery.map() method is a versatile tool for transforming arrays and objects with ease. Whether you need to modify array elements, manipulate object properties, or filter data, this method provides a convenient solution.

By mastering its usage, you can streamline data manipulation tasks within your web applications, enhancing efficiency and productivity.