7 Single-Line Helpful Functions in JavaScript

Ahh, Only 7 single-line functions will boost your development. JavaScript often requires more lines of code than necessary for common tasks. Sometimes, a single line is all you need to do the job efficiently.

Here are seven single-line functions that simplify your code and simplify your life.

1. Array Deduplication

Remove duplicates from an array using the Set object, which only stores unique values.

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const uniqueArray = arr => [...new Set(arr)];

Example: This function converts the array into a Set to remove duplicates and then back into an array.

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const numbers = [1, 2, 2, 3, 4, 4];
console.log(uniqueArray(numbers)); // [1, 2, 3, 4]

2. Check for Empty Object

Quickly check if an object is empty (i.e., has no own properties).

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const isEmptyObject = obj => Object.keys(obj).length === 0;

Example: This function uses Object.keys() to get an array of the object's own enumerable properties and check if its length is zero.

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const obj = {};
console.log(isEmptyObject(obj)); // true

3. Get a Random Element from the Array

Retrieve a random element from an array with a simple one-liner.

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const getRandomElement = arr => arr[Math.floor(Math.random() * arr.length)];

Example: This function calculates a random index and returns the element at that index in the array.

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const colors = ['red', 'green', 'blue'];
console.log(getRandomElement(colors)); // e.g., 'green'

4. Check if the Array Contains Value

Determine if an array contains a specific value using includes.

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const arrayContains = (arr, value) => arr.includes(value);

Example: This function checks if the value exists in the array and returns a boolean result.

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const fruits = ['apple', 'banana', 'cherry'];
console.log(arrayContains(fruits, 'banana')); // true

5. Convert String to Title Case

Convert a string to a title case where each word is capitalized.

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const toTitleCase = str => str.replace(/\b\w/g, char => char.toUpperCase());

Example: This function capitalizes the first letter of each word in the string using a regular expression.

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const title = 'hello world';
console.log(toTitleCase(title)); // 'Hello World'

6. Flatten Nested Arrays

Flatten a deeply nested array into a single-level array.

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const flattenArray = arr => arr.flat(Infinity);

Example: This function uses the flat() method with Infinity as the depth argument to handle any level of nesting.

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const nestedArray = [1, [2, [3, [4, [5]]]]];
console.log(flattenArray(nestedArray)); // [1, 2, 3, 4, 5]

7. Deep Merge Two Objects

Merge two objects deeply, combining properties recursively.

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const deepMerge = (obj1, obj2) => Object.assign({}, obj1, Object.keys(obj2).reduce((acc, key) => ({ ...acc, [key]: (typeof obj2[key] === 'object' && obj2[key] !== null && obj1[key] && typeof obj1[key] === 'object') ? deepMerge(obj1[key], obj2[key]) : obj2[key] }), {}));

Example: This function recursively merges two objects, combining properties from both objects while handling nested objects properly. It uses Object.assign() and reduce() to achieve a deep merge.

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const obj1 = { a: 1, b: { c: 2, d: 3 } };
const obj2 = { b: { d: 4, e: 5 }, f: 6 };
console.log(deepMerge(obj1, obj2)); // { a: 1, b: { c: 2, d: 4, e: 5 }, f: 6 }

Conclusion

Single-line functions can simplify and streamline your JavaScript code, making it both elegant and efficient. By leveraging concise patterns for common tasks, you enhance readability and maintainability, proving that less can indeed be more in coding.