freecodecamp: Basic algorithm Scripting

note code snip to remember

Reverse a String

" str= str.split("").reverse().join("");"

Factorialize a Number

" if(num===0)

return 1;

if(num<0)

return "negative";

else

return num*factorialize(num-1);"

Find the Longest Word in a String

" let words= str.split(' ');

words.sort((a,b)=> b.length - a.length);

return words[0].length;"

 Return Largest Numbers in Arrays

" arr.map(a4=>a4.sort((a,b)=>(b-a)));

return [arr[0][0],arr[1][0],arr[2][0],arr[3][0]];"

 Confirm the Ending

let lTarget=target.length;

let r= str.slice(str.length-lTarget,str.length);

return r===target;

Repeat a String Repeat a String

"function repeatStringNumTimes(str, num) {

// repeat after me

if(num<=0)

return '';

else

{

let r='';

for(let i=0;i<num;i++)

{

r+=str;

}

return r;

}

}"

Truncate a String

" if (num<=0)

return ;

else{

return (str.length<=num) ? str : str.slice(0,num) +"...";

}"

Finders Keepers

"function findElement(arr, func ) {

return arr.filter(func)[0];

//let num = 0;

//return num;

}

findElement([1, 2, 3, 4], num => num % 2 === 0);"

Boo who

" return (typeof bool === "boolean") ? true : false;"

Title Case a Sentence

" let toL= str.toLowerCase();

let aL= toL.split(' ');

let a= aL.map(a=>a[0].toUpperCase() + a.substr(1,a.length-1));

return a.join(' ');

}"

Slice and Splice

" let arr1Cpy= arr1.slice(0,arr1.length);

let arr2Cpy= arr2.slice(0,arr2.length);

let a= arr2Cpy.slice(0,n);

let b= arr2Cpy.splice(n,arr2Cpy.length);

let c= a.concat(arr1Cpy);

console.log(a);

console.log(b);

console.log(c);

return c.concat(b) ;"

Falsy Bouncer

"return arr.filter(Boolean);"

Where do I Belong

" arr.sort((a,b)=>a-b);

let i=0;

for(i;i<arr.length;i++)

{

if(num<=arr[i])

return i;

}

return i;

}"

Mutations

---

"function mutation(arr) {

let desArr1= arr[0].toLowerCase().split('');

let desArr2= arr[1].toLowerCase().split('');

desArr1.sort();

desArr2.sort();

let min;

let count=0;

let maxArr=[];

let minArr=[];

let desArr=[];

if(desArr1.length>=desArr2.length)

{

minArr=desArr2.slice(0,desArr2.length);

maxArr=desArr1.slice(0,desArr1.length);

min=desArr2.length;

}

else

{

minArr=desArr1.slice(0,desArr1.length);

maxArr=desArr2.slice(0,desArr2.length);

min= desArr1.length;

}

let max=maxArr.length;;

for(let i=0;i<max;i++){

for(let j=0;j<min;j++)

{

if((maxArr[i]==minArr[j]&&maxArr[i-1]!=maxArr[i]))

desArr.push(minArr[j])

}

}

if(desArr.length==min)

return true;

else

return false;

}

mutation(["hello", "hey"]);"

Chunky Monkey

"function chunkArrayInGroups(arr, size) {

// Break it up.

if(arr.length<=size)

return ;

let l=arr.length;

let step=size;

let r=[]

let begin=0;

let end=size;

let last;

while(step<=l)

{

r.push(arr.slice(begin,end));

begin=end;

last=step;

step+=size;

end=step;

}

if(l%size!=0)

r.push(arr.slice(last,l));

return r;

}

chunkArrayInGroups(["a", "b", "c", "d"], 2);"

""