Front End Technology Articles - Page 319 of 652

We are required to write a JavaScript function that takes in an array of nested arrays of Numbers and some falsy values (including 0) and some strings as well and the function should return the product of number values present in the nested array. If the array contains some 0s, we should ignore them as well.ExampleThe code for this will be −const arr = [    1, 2, null, [       2, 5, null, undefined, false, 5, [          1, 3, false, 0, 2       ], 4, false    ], 4, 6, 0 ... Read More

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 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 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 ]

We are required to write a JavaScript function that takes in a number and returns the difference of the sums of the digits at even place and the digits odd place.ExampleThe code for this will be −const num = 123456; const alternateDifference = (num, res = 0, ind = 0) => {    if(num){       if(ind % 2 === 0){          res += num % 10;       }else{          res -= num % 10;       };       return alternateDifference(Math.floor(num / 10), res, ++ind);    };    return Math.abs(res); }; console.log(alternateDifference(num));OutputThe output in the console −3

We have an array of numbers like this −const arr = [-1,-2,-1,0,-1,-2,-1,-2,-1,0,1,0];We are required to write a JavaScript function that counts the consecutive groups of negative numbers in the array.ExampleThe code for this will be −const arr = [-1,-2,-1,0,-1,-2,-1,-2,-1,0,1,0]; const countClusters = arr => {    return arr.reduce((acc, val, ind) => {       if(val < 0 && arr[ind+1] >= 0){          acc++;       };       return acc;    }, 0); }; console.log(countClusters(arr));OutputThe output in the console −2