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We are required to write a JavaScript function that takes in two strings and returns the count of the number of times the str1 appears in the str2.ExampleThe code for this will be −const main = 'This is the is main is string'; const sub = 'is'; const countAppearances = (main, sub) => { const regex = new RegExp(sub, "g"); let count = 0; main.replace(regex, (a, b) => { count++; }); return count; }; console.log(countAppearances(main, sub));OutputThe output in the console −4
We are required to write a JavaScript function that takes in Number arrays and returns the element from arrays that are not common to both.For example, if the two arrays are −const arr1 = [2, 4, 2, 4, 6, 4, 3]; const arr2 = [4, 2, 5, 12, 4, 1, 3, 34];OutputThen the output should be −const output = [ 6, 5, 12, 1, 34 ]ExampleThe code for this will be −const arr1 = [2, 4, 2, 4, 6, 4, 3]; const arr2 = [4, 2, 5, 12, 4, 1, 3, 34]; const deviations = (first, second) => { ... Read More
We are required to write a JavaScript function that takes in a number and returns true if it is a Pronic number otherwise returns false.A Pronic number is a number which is the product of two consecutive integers, that is, a number of the form −n(n + 1)ExampleThe code for this will be −const num = 132; const isPronic = num => { let nearestSqrt = Math.floor(Math.sqrt(num)) - 1; while(nearestSqrt * (nearestSqrt + 1)
We are required to write a JavaScript function that takes in an array of positive as well as negative Numbers and changes the positive numbers to corresponding negative numbers and the negative numbers to corresponding positive numbers in place.ExampleThe code for this will be −const arr = [12, 5, 3, -1, 54, -43, -2, 34, -1, 4, -4]; const changeSign = arr => { arr.forEach((el, ind) => { arr[ind] *= -1; }); }; changeSign(arr); console.log(arr);OutputThe output in the console −[ -12, -5, -3, 1, -54, 43, 2, -34, 1, -4, 4 ]
We are required to write a JavaScript function that takes in a string and swaps the adjacent words of that string with one another until the end of that string.ExampleThe code for this will be −const str = "This is a sample string only"; const replaceWords = str => { return str.split(" ").reduce((acc, val, ind, arr) => { if(ind % 2 === 1){ return acc; } acc += ((arr[ind+1] || "") + " " + val + " "); return acc; }, ""); }; console.log(replaceWords(str));OutputThe output in the console −is This sample a only string
We are required to write a JavaScript function that takes in two numbers, say m and n and returns two numbers whose sum is n and product is m. If there exist no such numbers than our function should return false.ExampleThe code for this will be −const goldenNumbers = (sum, prod) => { for(let i = 0; i < (sum / 2); i++){ if(i * (sum-i) !== prod){ continue; }; return [i, (sum-i)]; }; return false; }; console.log(goldenNumbers(24, 144)); console.log(goldenNumbers(14, 45)); console.log(goldenNumbers(21, 98));OutputThe output in the console −false [ 5, 9 ] [ 7, 14 ]
We are required to write a JavaScript function that takes in an array of strings and deletes every one of the two strings that start with the same letter.For example, If the actual array is −const arr = ['Apple', 'Jack' , 'Army', 'Car', 'Jason'];Then we have to delete and keep only one string in the array distinct letters, so one of the two strings starting with A should get deleted and the same should the one with J.ExampleThe code for this will be −const arr = ['Apple', 'Jack' , 'Army', 'Car', 'Jason']; const delelteSameLetterWord = arr => { const ... Read More
We have an array that contains some string values as well as some false values.We are required to write a JavaScript function that takes in this array and returns a string constructed by joining values of the array and omitting false values.ExampleThe code for this will be −const arr = ["Here", "is", null, "an", undefined, "example", 0, "", "of", "a", null, "sentence"]; const joinArray = arr => { const sentence = arr.reduce((acc, val) => { return acc + (val || ""); }, ""); return sentence; }; console.log(joinArray(arr));OutputThe output in the console −Hereisanexampleofasentence
We are required to write a JavaScript function that takes in a negative integer and returns the sum of its digits.For example: If the number is −-5456OutputThen the output should be −5+4+5+6 10ExampleThe code for this will be −const num = -5456; const sumNum = num => { return String(num).split("").reduce((acc, val, ind) => { if(ind === 0){ return acc; } if(ind === 1){ acc -= +val; return acc; }; acc += +val; return acc; }, 0); }; console.log(sumNum(num));OutputThe output in the console −10
We are required to write a JavaScript function that takes in an array of numbers with duplicate entries and sums all the duplicate entries to one index.ExampleThe code for this will be −const input = [1, 3, 1, 3, 5, 7, 5, 3, 4]; const sumDuplicate = arr => { const map = arr.reduce((acc, val) => { if(acc.has(val)){ acc.set(val, acc.get(val) + 1); }else{ acc.set(val, 1); }; return acc; }, new Map()); return Array.from(map, el => el[0] * el[1]); }; console.log(sumDuplicate(input));OutputThe output in the console −[ 2, 9, 10, 7, 4 ]