Top 50 One-Liners JavaScript

Mastering JavaScript: Top 50 One-Liners Every Developer Should Know

Introduction:

JavaScript is a versatile and powerful programming language used extensively in web development. Whether you're a seasoned developer or just starting your journey, mastering JavaScript can significantly boost your productivity and efficiency. In this article, we'll explore the top 50 JavaScript one-liners that every developer should know. These concise and elegant solutions cover a wide range of common tasks, from manipulating arrays to working with strings and objects.

1. Checking if a Variable is Undefined:

const isUndefined = variable => typeof variable === 'undefined';

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2. Checking if a Variable is Null:

const isNull = variable => variable === null;

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3. Checking if a Variable is Empty:

const isEmpty = variable => !variable;

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4. Checking if a Variable is an Array:

const isArray = variable => Array.isArray(variable);

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5. Checking if a Variable is an Object:

const isObject = variable => typeof variable === 'object' && variable !== null;

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6. Checking if a Variable is a Function:

const isFunction = variable => typeof variable === 'function';

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7. Getting the Last Element of an Array:

const lastElement = array => array.slice(-1)[0];

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8. Flattening an Array:

const flattenArray = array => array.flat();

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9. Reversing a String:

const reverseString = str => str.split('').reverse().join('');

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10. Generating a Random Number:

const randomNumber = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;

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11. Removing Duplicates from an Array:

const removeDuplicates = array => [...new Set(array)];

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12. Checking if an Array Contains a Specific Value:

const containsValue = (array, value) => array.includes(value);

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13. Checking if a String Contains a Substring:

const containsSubstring = (str, substring) => str.includes(substring);

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14. Getting the Current Date and Time:

const currentDateTime = () => new Date().toLocaleString();

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15. Checking if a Year is a Leap Year:

const isLeapYear = year => (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;

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16. Truncating a Number to a Specified Decimal Place:

const truncateNumber = (num, decimalPlaces) => Math.trunc(num * 10 ** decimalPlaces) / 10 ** decimalPlaces;

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17. Checking if an Object has a Specific Property:

const hasProperty = (obj, property) => obj.hasOwnProperty(property);

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18. Converting a String to Title Case:

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

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19. Repeating a String N Times:

const repeatString = (str, n) => str.repeat(n);

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20. Generating a Range of Numbers:

const range = (start, end) => Array.from({ length: end - start + 1 }, (_, i) => start + i);

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21. Summing Numbers in an Array:

const sumArray = array => array.reduce((acc, curr) => acc + curr, 0);

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22. Getting the Maximum Value in an Array:

const maxArrayValue = array => Math.max(...array);

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23. Getting the Minimum Value in an Array:

const minArrayValue = array => Math.min(...array);

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24. Checking if a Number is Even:

const isEven = num => num % 2 === 0;

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25. Checking if a Number is Odd:

const isOdd = num => num % 2 !== 0;

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26. Checking if a String is Palindrome:

const isPalindrome = str => str === str.split('').reverse().join('');

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27. Reversing the Order of Words in a String:

const reverseWords = str => str.split(' ').reverse().join(' ');

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28. Checking if a Number is Prime:

const isPrime = num => {
    for (let i = 2; i <= Math.sqrt(num); i++) {
        if (num % i === 0) return false;
    }
    return num > 1;
};

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29. Converting Fahrenheit to Celsius:

const fahrenheitToCelsius = f => (f - 32) * 5 / 9;

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30. Converting Celsius to Fahrenheit:

const celsiusToFahrenheit = c => (c * 9 / 5) + 32;

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31. Factorial of a Number:

const factorial = n => n === 0 ? 1 : n * factorial(n - 1);

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32. Fibonacci Sequence:

const fibonacci = n => n <= 1 ? n : fibonacci(n - 1) + fibonacci(n - 2);

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33. Finding the Greatest Common Divisor (GCD) of Two Numbers:

const gcd = (a, b) => b === 0 ? a : gcd(b, a % b);

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34. Finding the Least Common Multiple (LCM) of Two Numbers:

const lcm = (a, b) => (a * b) / gcd(a, b);

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34. Shuffle an Array:

const shuffleArray = array => array.sort(() => Math.random() - 0.5);

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35. Checking if a Number is a Perfect Square:

const isPerfectSquare = num => Math.sqrt(num) % 1 === 0;

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36. Checking if a Number is a Power of Two:

const isPowerOfTwo = num => (num & (num - 1)) === 0 && num !== 0;

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37. Checking if a Number is a Palindrome:

const isPalindromeNumber = num => num.toString() === num.toString().split('').reverse().join('');

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38. Capitalize the First Letter of Each Word in a Sentence:

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

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39. Counting the Occurrences of Each Element in an Array:

const countOccurrences = array => array.reduce((acc, val) => {
  acc[val] = (acc[val] || 0) + 1;
  return acc;
}, {});

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40. Sum of Squares of Digits of a Number:

const sumOfSquareDigits = num => num.toString().split('').reduce((acc, digit) => acc + Math.pow(parseInt(digit), 2), 0);

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41. Converting a Number to Binary:

const toBinary = num => num.toString(2);

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42. Converting a Binary Number to Decimal:

const binaryToDecimal = binary => parseInt(binary, 2);

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43. Checking if a String is an Anagram of Another String:

const isAnagram = (str1, str2) => str1.split('').sort().join('') === str2.split('').sort().join('');

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44. Converting an Object to Query Parameters String:

const objectToQueryString = obj => Object.entries(obj).map(([key, value]) => `${encodeURIComponent(key)}=${encodeURIComponent(value)}`).join('&');

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45. Checking if a Year is a Leap Year (Using Ternary Operator):

const isLeapYear = year => (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0 ? true : false;

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46. Reversing an Array in Place:

const reverseArrayInPlace = array => array.reverse();

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47. Finding the Maximum Value in an Array (Using Spread Operator):

const maxArrayValue = array => Math.max(...array);

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48. Finding the Minimum Value in an Array (Using Spread Operator):

const minArrayValue = array => Math.min(...array);

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49. Truncating a String to a Maximum Length and Appending Ellipsis:

const truncateString = (str, maxLength) => str.length > maxLength ? str.slice(0, maxLength) + '...' : str;

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50. Finding the Longest Word in a Sentence:

const longestWord = sentence => sentence.split(' ').reduce((longest, current) => current.length > longest.length ? current : longest, '');

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Conclusion: JavaScript one-liners are concise and powerful solutions to common programming tasks. By mastering these one-liners, you can write cleaner, more efficient code and become a more proficient JavaScript developer. Experiment with these examples and incorporate them into your projects to take your coding skills to the next level. Happy coding!