Top 10 String Javascript Interview Coding Question

function reverseString(str) { return str.split('').reverse().join(''); } console.log(reverseString("hello")); // Output: "olleh" 

function numberToWords(number) { const singleDigits = ['', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']; const teens = ['ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']; const tens = ['', '', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety']; if (number === 0) { return 'zero'; } if (number < 10) { return singleDigits[number]; } if (number < 20) { return teens[number - 10]; } if (number < 100) { return tens[Math.floor(number / 10)] + ' ' + singleDigits[number % 10]; } if (number < 1000) { return singleDigits[Math.floor(number / 100)] + ' hundred ' + numberToWords(number % 100); } if (number < 1000000) { return numberToWords(Math.floor(number / 1000)) + ' thousand ' + numberToWords(number % 1000); } if (number < 1000000000) { return numberToWords(Math.floor(number / 1000000)) + ' million ' + numberToWords(number % 1000000); } return 'Number too large to convert'; } // Example usage: console.log(numberToWords(123)); // Outputs: ""one hundred twenty three"" console.log(numberToWords(12345)); // Outputs: ""twelve thousand three hundred forty five"" console.log(numberToWords(123456789)); // Outputs: ""one hundred twenty three million four hundred fifty six thousand seven hundred eighty nine""" 

function countVowelsAndConsonants(str: string): { vowels: number, consonants: number } { // Define a regular expression to match vowels (case-insensitive) const vowelRegex = /[aeiou]/i; let vowels = 0; let consonants = 0; // Convert the string to lowercase for case-insensitive comparison const lowerCaseStr = str.toLowerCase(); // Iterate through each character of the string for (let char of lowerCaseStr) { // Check if the character is a letter if (/[a-z]/i.test(char)) { // Increment the count of vowels if the character is a vowel if (vowelRegex.test(char)) { vowels++; } else { // Increment the count of consonants if the character is a consonant consonants++; } } } // Return the count of vowels and consonants return { vowels, consonants }; } // Example usage: const inputString = ""Hello World""; const { vowels, consonants } = countVowelsAndConsonants(inputString); console.log(""Vowels:"", vowels); // Output: 3 console.log(""Consonants:"", consonants); // Output: 7 

function calculateTwoLargestVowelCounts(str: string): number[] { // Define an array to store counts of each vowel (a, e, i, o, u) const vowelCounts: number[] = [0, 0, 0, 0, 0]; // Convert the string to lowercase for case-insensitive comparison const lowerCaseStr = str.toLowerCase(); // Iterate through each character of the string for (let char of lowerCaseStr) { // Check if the character is a vowel switch (char) { case 'a': vowelCounts[0]++; break; case 'e': vowelCounts[1]++; break; case 'i': vowelCounts[2]++; break; case 'o': vowelCounts[3]++; break; case 'u': vowelCounts[4]++; break; } } // Sort the array in descending order to find the two largest counts const sortedCounts = vowelCounts.slice().sort((a, b) => b - a); // Return the two largest counts return sortedCounts.slice(0, 2); } // Example usage: const inputString = ""Hello World""; const twoLargestCounts = calculateTwoLargestVowelCounts(inputString); console.log(""Two Largest Vowel Counts:"", twoLargestCounts); // Output: [2, 1]