JS Equivalent to Python Get
Last Updated :
23 Dec, 2024
In Python, the get() method is often used with dictionaries to retrieve values associated with a given key, while providing a default value if the key does not exist. JavaScript, however, does not have a built-in get() method for objects. In this article, we will explore different methods to replicate Python’s get() behavior in JavaScript.
What is Python's get() Method?
Python's get() method is used to retrieve the value for a given key from a dictionary and if the key does not exist, it returns a specified default value instead of raising a KeyError.
Example:
Python
dict = {"name": "Shivang", "age": 22}
a = dict.get("name", "Unknown")
b = dict.get("city", "Unknown")
print(a)
print(b)
Explanation:
- As seen in the example, the get() method returns the value of the name key if it exists, or "Unknown" if it does not.
JavaScript Equivalent to Python Get
Below are the methods and the approaches to show the equivalence between JavaScript and Python get() function:
Using the in Operator
The in operator can be used to check if a key exists in an object before accessing it. If the key does not exist, a default value can be returned.
Example:
JavaScript
const dict = { name: "Shivang", age: 22 };
const name = "name" in dict ? dict.name : "Unknown";
const city = "city" in dict ? dict.city : "Unknown";
console.log(name);
console.log(city);
Explanation:
- In this method, the in operator checks if the key exists in the object and returns the corresponding value or a default value if the key is not found.
Using the Logical OR (||) Operator
The logical OR operator can be used to provide a default value if the key does not exist in the object.
Example:
JavaScript
const dict = { name: "Shivang", age: 22 };
const name = dict.name || "Unknown";
const city = dict.city || "Unknown";
console.log(name);
console.log(city);
Explanation:
- In this method, if the key does not exist or the value is falsy (e.g., undefined, null, 0, ""), the default value is returned.
Using the Nullish Coalescing Operator (??)
The nullish coalescing operator is a more recent addition to JavaScript (ES2020) and is similar to the logical OR operator but only returns the right-hand side if the left-hand side is null or undefined.
Example:
JavaScript
const dict = { name: "Shivang", age: 22 };
const name = dict.name ?? "Unknown";
const city = dict.city ?? "Unknown";
console.log(name);
console.log(city);
Explanation:
- This method ensures that the default value is returned only if the key does not exist or if the value is null or undefined.
Using a Custom Function
A custom function can be created to mimic the behavior of Python’s get() method.
Example:
JavaScript
function get(obj, key, defaultValue) {
return key in obj ? obj[key] : defaultValue;
}
const dict = { name: "Shivang", age: 22 };
const name = get(dict, "name", "Unknown");
const city = get(dict, "city", "Unknown");
console.log(name);
console.log(city);
Explanation:
- This custom function checks if the key exists in the object and returns the corresponding value or the specified default value.
Similar Reads
Js Equivalent to Python In In Python, it is used for iterating over elements, checking membership and even used for conditional checks. JavaScript offers similar functionality with different syntax and behavior. This article discusses how Python's in keyword works in different contexts and how to achieve similar behavior in J
3 min read
JS Equivalent to Python Slicing In Python, slicing is a feature that allows us to extract portions of a sequence such as lists, strings and tuples using a simple syntax. However, JavaScript does not have a direct equivalent to Pythonâs slicing syntax. Fortunately, there are several ways to achieve similar functionality in JavaScri
4 min read
Javascript equivalent to Python Dictionary A dictionary is a powerful data structure allowing us to store and access data using keys quickly. In Python, we use a dictionary to store key-value pairs. In JavaScript, the closest equivalent to a Python dictionary is the Object or Map. The choice between a JavaScript Object or Map depends on the
3 min read
JS equivalent to Python List comprehension Pythonâs list comprehension is an efficient way to create lists by performing operations on each item of an existing iterable, such as a list or range. JavaScript doesn't have a built-in list comprehension feature but it provides several methods to achieve similar functionality. In this article, we
3 min read
turtle.getpen() function in Python The turtle module provides turtle graphics primitives, in both object-oriented and procedure-oriented ways. Because it uses Tkinter for the underlying graphics, it needs a version of Python installed with Tk support. turtle.getpen() This function is used to return the Turtleobject itself. It doesn't
1 min read
How to JSON decode in Python? When working with JSON data in Python, we often need to convert it into native Python objects. This process is known as decoding or deserializing. The json module in Python provides several functions to work with JSON data, and one of the essential tools is the json.JSONDecoder() method. This method
5 min read