fccStuffs/challs.md at master · codeAWgit/fccStuffs

Functions created in Algorithm section

Reverse a string (done without higher order functions)

let reverseString = (str) => { let newStr = '' for(var i = str.length; i > 0; i--){ newStr += str.charAt(i-1) } return newStr }

Factorialize a Number

First way I learned to make this function.

function factorialize(num) { let result = 1 for (let i = 1; i <= num ; i++){ result *= i; } return result; }

Second way I learned to make this function.

function factorialize(num) { if (num == 1 || !num){ return 1} return num * factorialize(num-1) }

(done using the ternary style for if / else statement)

let factorialize = (num) => num == 1 || !num ? 1 : num * factorialize(num-1)

or for tail call optimization

let factorialize = (num, acc = 1 ) { if (num < 2 ) return acc return factorialize(num - 1, num * acc) }

Check for palindromes

let palindrome = (str) => { str = str.replace(/_|\W+/g, '').toLowerCase() str2 = str.split('').reverse().join('') return str === str2 }

Find the Longest Word in a String

let findLongestWord = (str) => { return Math.max.apply(null, str.split(' ').map(x => x.length)); }

Title Case a Sentence

let titleCase = (str) => { return str.toLowerCase() .split(' ') .map(x => { x = x.split('') x[0] = x[0].toUpperCase() return x.join('') }) .join(' ') }

Return Largest Number in Arrays

let largestOfFour = (arr) => { return arr.map(x => Math.max.apply(null, x)) }

Confirm the Ending

let confirmEnding = (str, target) => { let len = target.length return target === str.substr(0-len,len) }

Repeat a String Repeat a String

let repeatStringNumTimes = (str, num) => { if(num < 1) num = 0 return str.repeat(num); }

Truncate a String

let truncateString = (str, num) => { return (num <= 3) ? str.slice(0,num) + '...' : (str.length <= num) ? str.slice(0,num) : str.slice(0,num - 3) + '...' }

Chunky Monkey

let chunkArrayInGroups = ( arr, size, newRay = [] ) => { while( arr.length ) { newRay.push( arr.splice( 0,size )) } return newRay }

Slasher Flick

let slasher = (arr, howMany) => { return arr.slice(howMany); }

Mutations

let mutation = (arr) => { arr[1].toLowerCase().split('').forEach( x => { if (arr[0].toLowerCase().indexOf(x) === -1) arr[0] = '' }) return Boolean(arr[0]); }

Falsy Bouncer

let bouncer = (arr) => { return arr.filter( x => x ) }

Seek and Destroy

function destroyer(arr) { let i = arguments.length; while( i-- ){ arr = arr.filter(x => x !== arguments[i]) } return arr; }

Where Do I Belong?

let getIndexToIns = (arr, num) => { arr.push(num) return arr.sort((a, b) => a - b).indexOf(num) }

Caesar's Cipher

let rot13 = (str) => { // LBH QVQ VG! let deCodeROT13 = m => { return String.fromCharCode(m.charCodeAt() + (/[A-M]/.test(m) ? 13 : -13)) } return str.replace(/\w/g, deCodeROT13) }

Sum All Numbers in a Range

let sumAll = (arr, rslt = 0) => { arr.sort( (a,b) => a - b) do{ rslt += arr[0]
} while (arr[1] > arr[0]++) return rslt }

Diff Two Arrays

function diffArray(arr1, arr2) { return [...arr1,...arr2] .filter( x => arr1.indexOf(x) == -1 || arr2.indexOf(x) == -1) }

Roman Numeral Converter

function convertToRoman(num) { num = '0'.repeat(4 - String(num).length) + String(num) let fStr = ''

for(let i = 0, len = num.length ; i < len ; i++){
    if (+num[i] === 0) continue
    let lettersToUse = [['_X','_V','M'],['M','D','C'],['C','L','X'],['X','V','I']]                 
    fStr += buildRoman(+num[i], ...lettersToUse[i])
}

function buildRoman(digit, t, f, o){
    return (digit === 9) ? o + t :
            (digit === 4) ? o + f :
            (digit === 5) ? f :
            (digit < 4) ? o.repeat(digit) :
            f + o.repeat(digit - 5)
}
return fStr

}

Wherefore Art Thou

function whatIsInAName(collection, source) { var arr = []; for ( let element of collection) { let inElement = true for ( let prop in source) { if ( !(prop in element) || source[prop] !== element[prop] && inElement) { inElement = false } } if (inElement) arr.push(element) } return arr; }

Search and Replace

function myReplace(str, before, after) { return str.replace(before, preverveCase())

function preverveCase() {
    if ( before.charCodeAt(0) < 91 ) {
        return after.charAt(0).toUpperCase() + after.slice(1)
    }
    return after
}

}

Pig Latin

function translatePigLatin(str) { str = str.replace(/(\b[aeiou]\w+)/, '$1way') return str.replace(/(\b[^aeiou]+)(\w+)/, '$2$1ay') }

DNA Pairing

function pairElement(str) { return str.split('').map( x => { return ( x == 'G') ? ['G','C'] : ( x == 'C') ? ['C','G'] : ( x == 'A') ? ['A','T'] : ( x == 'T') ? ['T','A'] : "Not a DNA character" }) }

Missing Letters

function fearNotLetter(str) { let len = str.length, i = 1 for ( ; i < len; i++) { if ( str.charCodeAt( i - 1 ) !== ( str.charCodeAt( i ) - 1 )) { return String.fromCharCode(str.charCodeAt( i ) - 1 ) } } return undefined }

Boo Who

function booWho(bool) { return bool === true || bool === false; }

Sorted Union

function uniteUnique(arr) { let tmpArr
[arr, ...tmpArr] = arguments tmpArr.forEach( x => { arr = arr.concat(x.filter( y => !(arr.includes(y)))) }) return arr }

Convert HTML Entities

function convertHTML(str) { str = str.replace(/&/g, "&") str = str.replace(/"/g, """) str = str.replace(/'/g, "'") str = str.replace(/</g, "<") return str.replace(/>/g, ">") }

Spinal Tap Case

function spinalCase(str) { return str.replace(/(\S)\s+(\S)|([a-z]+)_?([A-Z]{1})/g, '$1$3-$2$4').toLowerCase(); }

Sum All Odd Fibonacci Numbers

function sumFibs(num) { let o = 1, o2 = 1, next = 2, sum = 2; while ( next <= num ) { o2 = o; o = next; next = o + o2 sum += o % 2 && o } return sum; }

Sum All Primes

function sumPrimes(num) { let sum = 0 for ( let i = 2; i <= num; i++) { let quot = 0 for (let k = 1; k <= i; k++) { if ( i % k === 0 ) quot += k } if ( i + 1 === quot ) sum += i } return sum }

Smallest Common Multiple

Finders Keepers

function findElement(arr, func) { return arr.find(func); }

Drop It

function dropElements(arr, func) { let sliceFrom = arr.reduce( (rslt, cur, i) => { return rslt === arr.length && func(cur) ? i : rslt }, arr.length) return arr.slice(sliceFrom); }

Steamroller

function steamrollArray(arr) { let rsltArr = [] arr.forEach( x => { ( Array.isArray( x ) ) ? ( steamrollArray( x ).forEach( y => rsltArr.push( y ) ) ) : ( rsltArr.push( x ) ) }) return rsltArr }

Binary Agents

function binaryAgent(str) { return str.split(' ').map( x => String.fromCharCode( parseInt( x, 2 )) ).join('') }

Everything Be True

function truthCheck(collection, pre) { return collection.every( x => Boolean(x[pre])); }

Arguments Optional

function addTogether() { let sum = 0 for ( let i =0; i < arguments.length; i++) { typeof arguments[i] !== 'number' ? sum = undefined : sum += arguments[i] } if ( arguments.length > 1 || sum === undefined ) { return sum } else {
return function needNum( secondNum ) { return ( typeof secondNum !== 'number' ) ? undefined : sum + secondNum } }
}

Validate US Telephone Numbers

function telephoneCheck(str) { let tF = /^1?\s?\d{3}-?\s?\d{3}-?\s?\d{4}$/.test(str); return tF || /^1?\s?[(]\d{3}[)]-?\s?\d{3}-?\s?\d{4}$/.test(str); }

Record Collection

Old

New

function updateRecords(id, prop, value) { if ( prop != 'tracks' ) collection[id][prop] = value if ( prop == 'tracks' && prop in collection[id] ) { collection[id][prop].push( value ) }
if ( prop == 'tracks' && !(prop in collection[id]) ) { collection[id][prop] = [ value ] } if ( !value ) delete collection[id][prop] return collection; }

Symmetric Difference

Old

New

Exact Change

Old

  drawerTotal += cid[8-i][1] * 100;
}

if (amntToReturn > 0){ return "Insufficient Funds"; } if (drawerTotal == 0){ return "Closed"; }
return change; }

New

Inventory Update

Old

New

function updateInventory(arr1, arr2) { let arr1Names = [] arr1.forEach( e => arr1Names.push( e[1] )) arr2.forEach( e => { if ( !arr1Names.includes( e[1] ) ) arr1.push( e ) else { arr1[ arr1Names.indexOf( e[1] ) ][0] += e[0] } }) return arr1.sort( (a, b) => a[1] < b[1] ? -1 : 1 ) }

Newer Still

function updateInventory(arr1, arr2) { arr2.forEach( e => { var i = arr1.findIndex( x => x[1] === e[1] ); i === -1 ? arr1.push( e ) : arr1[ i ][0] += e[0]; }) return arr1.sort( (a, b) => a[1] < b[1] ? -1 : 1 ) }

No repeats please

Old

New

YT_watch?v=B5lUyJDkWzE

Make a Person

Old

var Person = function(firstAndLast) { // Complete the method below and implement the others similarly this.setFirstName = function(first){ if(!this.fullName){ this.fullName = firstAndLast; }
this.fullName = this.fullName.replace(/\w+/, first); //To replace first name. };

this.setLastName = function(last){ if(!this.fullName){ this.fullName = firstAndLast; }
this.fullName = this.fullName.replace(/(\w+\s+)(\w+)/, '$1' + last); //Replace last name. };

this.setFullName = function(firstAndLast2){ this.fullName = firstAndLast2; };

this.getFirstName = function() { if(!this.fullName){ this.fullName = firstAndLast; } return this.fullName.replace(/(\w+)(\s+\w+)/, '$1'); };

this.getLastName = function() { if(!this.fullName){ this.fullName = firstAndLast; }
return this.fullName.replace(/(\w+\s+)(\w+)/, '$2'); };

this.getFullName = function() {
return this.fullName; };
};

New

Map the Debris

function orbitalPeriod(arr) { var GM = 398600.4418; var earthRadius = 6367.4447; arr = arr.map( function (x) { x.orbitalPeriod = Math.round( 2 * Math.PI * Math.sqrt( Math.pow( x.avgAlt + earthRadius, 3 ) / GM )); delete x.avgAlt; return x; }); return arr; }

Pairwise

Old

function pairwise(arr, arg) { arr = arr.reduce(function(accOrI, curr, index, array){

array.find(function(x, index2){
  if(arg - curr == x && accOrI.indexOf(index) == -1 && accOrI.indexOf(index2) == -1 && index != index2){
    accOrI.push(index2);
    accOrI.push(index);
  }
});
return accOrI;

} return arr.reduce(function(sum, curVal){ return sum + curVal; }, 0); }, []);

New

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