I am doing the freecodecamp algorithmic challenge "Caesars Cipher". I have a problem with my code. I try to generate a lookup table as a dynamic object and for some reason it doesn't register. When doing console.log it is says "lookup table is undefined". It is the same with the Acode variable. If I comment out the console.logs then it will work but it will not encrypt anything because of the below part which checks if the char from strArr exists in the lookupTable, if not, it should assign the same value to the encryptedArr (this was done to not encrypt commas, spaces etc):
strArr.forEach(function(thisArg) {
var newValue;
if(lookupTable[thisArg] !== undefined ) {
newValue = lookupTable[thisArg];
} else {
newValue = thisArg;
}
encryptedArr.push(newValue);
});
Ofcourse lookupTable[thisArg] is always undefined.
Here is the whole function with the above part as well:
function rot13(str) { // LBH QVQ VG!
var strArr;
var encryptedArr = [];
var Acode;
var lookupTable = {}; //this object will contain the mapping of letters
var encryptedString;
//check the code of A , this will be a reference for the first letter as the algorith will use Modular Arithmetic
Acode = 'A'.charCodeAt(0);
console.log(Acode);
//generate an object containing mappings (I din't want to do it initially but theoreticaly just making lookups in a table would be more efficiant for huge workloads than calculating it every time)
//this algorithm is a little bit complecated but i don't know how to do modular arithmetic in code properly so I use workarrounds. If a = 101 then I do 101 + the remainder from current letter((Acode + 1) - 13) divided by 26 which works
for (i = 0; i < 26; i++) {
lookupTable[String.fromCharCode(Acode + i)] = String.fromCharCode(Acode + ((Acode + i) - 13) % 26);
console.log(lookupTable[String.fromCharCode(Acode + i)]);
}
//save the string into the array
strArr = str.split("");
//change letters into numbers and save into the code array
strArr.forEach(function(thisArg) {
var newValue;
if (lookupTable[thisArg] !== undefined) {
newValue = lookupTable[thisArg];
} else {
newValue = thisArg;
}
encryptedArr.push(newValue);
});
encryptedString = encryptedArr.join("");
return encryptedString;
}
// Change the inputs below to test
rot13("SERR PBQR PNZC");
console.log(Acode);
What am I doing wrong with the lookupTable object creation AND with the below?
Acode = 'A'.charCodeAt(0);
There's no undefined variable. The problem with your code is in how you calculate the lookup table entries. Your code is mapping every character to itself, not shifting by 13. The correct formula is
Acode + ((i + 13) % 26)
Acode is the ASCII code for the letter, and you shouldn't be including that when performing the modular shift. You just want to apply the modulus to the offset from the beginning of the alphabet after shifting it by 13.
function rot13(str) { // LBH QVQ VG!
var strArr;
var encryptedArr = [];
var Acode;
var lookupTable = {}; //this object will contain the mapping of letters
var encryptedString;
//check the code of A , this will be a reference for the first letter as the algorith will use Modular Arithmetic
Acode = 'A'.charCodeAt(0);
// console.log(Acode);
//generate an object containing mappings (I din't want to do it initially but theoreticaly just making lookups in a table would be more efficiant for huge workloads than calculating it every time)
//this algorithm is a little bit complecated but i don't know how to do modular arithmetic in code properly so I use workarrounds. If a = 101 then I do 101 + the remainder from current letter((Acode + 1) - 13) divided by 26 which works
for (i = 0; i < 26; i++) {
lookupTable[String.fromCharCode(Acode + i)] = String.fromCharCode(Acode + ((i + 13) % 26));
// console.log(lookupTable[String.fromCharCode(Acode + i)]);
}
//save the string into the array
strArr = str.split("");
//change letters into numbers and save into the code array
strArr.forEach(function(thisArg) {
var newValue;
if (lookupTable[thisArg] !== undefined) {
newValue = lookupTable[thisArg];
} else {
newValue = thisArg;
}
encryptedArr.push(newValue);
});
encryptedString = encryptedArr.join("");
return encryptedString;
}
// Change the inputs below to test
var result = rot13("SERR PBQR PNZC");
console.log(result);
Related
I want to split lower, upper & also the value of textBox without using .split() and also I want
to find the length of the string without using .length. Can anybody solve my problem I am tried but
I cannot find the exact logic for this problem.
var lowercase = "abcdefghijklmnopqrstuvwxyz";
var uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
function Print() {
var input = document.getElementById('demo').value;
document.write(document.getElementById('demo1').innerHTML = toUpper(input));
}
function toUpper(input) {
var upperCase = uppercase.split(""); //other way to split uppercase
var lowerCase = lowercase.split(""); //other way to split lowercase
var inputText = input.split(""); //other way to split input
var newText = "";
var found;
for (var i = 0; i < inputText.length; i++) { //not using .length to other way to find the size of inputText
found = false;
for (var ctr = 0; ctr < lowerCase.length; ctr++) { //not using .length other way to find the size of lowerCase
if (inputText[i] == lowerCase[ctr]) {
found = true;
break;
}
}
if (found) { //true
newText = newText + upperCase[ctr];
} else {
newText = newText + inputText[i];
}
}
return newText;
}
You can count the length of a string using the array function reduce.
Reduce loops over all elements in an array and executes a function you give it to reduce it to one value, you can read more here.
To get reduce working on strings, you need to use Array.from, like this:
Array.from(lowerCase).reduce((sum, carry) => sum + 1, 0) // 26
Reduce accepts a starting argument, which we set to zero here.
This way you do not need to use the split or length functions.
You don't need to check if the input is in a string either, you can use charCodeAt() and fromCharCode().
If you take your input and loop through it using Array.from() then forEach, you can get something which looks like this:
function print() {
const input = document.querySelector('#input').value;
document.querySelector('#target').value = stringToUpper(input);
}
function stringToUpper(input) {
let output = "";
Array.from(input).forEach(char => output += charToUpper(char));
return output;
}
function charToUpper(char) {
let code = char.charCodeAt(0);
code >= 97 && code <= 122 ? code -= 32 : code;
return String.fromCharCode(code);
}
<div>
<input id="input" placeholder="enter text here">
</div>
<button onclick="print()">To Upper</button>
<div>
<input id="target">
</div>
The key line is where we take the output and add the char (as upper) to it:
output += charToUpper(char)
If you don't know about arrow functions, you can read more here
This line:
code >= 97 && code <= 122 ? code -= 32 : code;
is just checking if the char is lower case (number between 97 and 122) and if so, subtracting 32 to get it to upper case.
The reason it is subtract not add is in utf-16, the chars are laid out like this:
ABCDEFGHIJKLMNOPQRTUWXYZabcdefghijklmnopqrtuwxyz
See here for more
I don't know what you mean by "split the value of textBox", but one way to determine the length of a string without using .length would be to use a for...of loop and have a counter increment each time it runs to keep track of the number of characters in the string.
let string = 'boo'
let lengthCounter = 0
for (let char of string) {
lengthCounter++
}
//lengthCounter = 3
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of
You can define your own split and length functions:
function mySplit(a){
var counter = 0;
rslt = [];
var val = a[counter];
while(typeof val != "undefined"){
rslt.push(a[counter]);
counter ++;
val = a[counter];
}
return rslt;
}
function myLength(a){
var counter = 0;
var val = a[counter];
while(typeof val != "undefined"){
counter ++;
val = a[counter];
}
return counter;
}
Your function now should be like:
function toUpper(input) {
var upperCase = mySplit(uppercase);
var lowerCase = mySplit(lowercase);
var inputText = mySplit(input);
var newText = "";
var found;
for (var i = 0; i < myLength(inputText); i++) {
found = false;
for (var ctr = 0; ctr < myLength(lowerCase); ctr++) {
if (inputText[i] == lowerCase[ctr]) {
found = true;
break;
}
}
if (found) { //true
newText = newText + upperCase[ctr];
} else {
newText = newText + inputText[i];
}
}
return newText;
}
The simplest way would be to just use the build in function of javascript .toUpperCase() (see example 1). https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
Else if you insist on using a for.loop you may do so aswell (see example two). You do not need the split() function since a string already is an arrayof characters. Also be aware that not all characters in the web have lowercase counterparts, so the logic itself is flawed.
//REM: This lines are not required.
/*
var lowercase = "abcdefghijklmnopqrstuvwxyz";
var uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
function Print() {
var input = document.getElementById('demo').value;
document.write(document.getElementById('demo1').innerHTML = toUpper(input));
}
*/
//REM: Version 1 (using string.toUpperCase())
(function toUpper1(input){
var tReturn = (input || '').toUpperCase();
console.log('toUpper1', tReturn);
return tReturn
}('abcDEFghiJKL'));
//REM: Version 2 (using your way)
(function toUpper2(input){
var tReturn = '';
if(input && input.length){
for(let i=0, j=input.length; i<j; i++){
tReturn += (input[i] === input[i].toLowerCase()) ? input[i].toUpperCase() : input[i]
}
};
console.log('toUpper2', tReturn);
return tReturn
}('abcDEFghiJKL'));
I want to generate keys in alphabetical order in such a way that it begins with
aaaaa
then the next would be aaaab and after reaching to aaaaz the string should be aaaba and then aaabb and so on , so that the keys generate properly
My sample JSON to be created
var keygen={aaaaa,
aaaab,
aaaac .........aaaaz,aaaba ....}
my javascript
$scope.doKeyGen=function(lastValueInJSON)
{ // Do something
}
This will work for you. JS Fiddle is here.
https://jsfiddle.net/3d789okv/7/
Make sure that you the last value you give will be hit.
Otherwise you are going to an infinite loop hell.
Also you can configure the number of letters in the call to getNext().
But make sure that you set the equal number of letters in the first value and "aaaaa" and the last value "asxas"
String.prototype.replaceAt=function(index, replacement) {
return this.substr(0, index) + replacement+ this.substr(index + replacement.length);
}
var json = [];
function getNext(charCount,lastValue){
changeIndex = charCount -1;
var newValue = "";
while (changeIndex >= 0){
if(lastValue[changeIndex] !== "z"){
var changed = lastValue[changeIndex];
var replacechanged = String.fromCharCode(changed.charCodeAt(0)+1);
newValue = lastValue.replaceAt(changeIndex,replacechanged)
for(var j=changeIndex+1; j < charCount; ++j){
newValue = newValue.replaceAt(j,"a");
}
return newValue;
}
changeIndex--;
}
}
function createJSON(lastValue){
if(!json.length){
//var startPrefix = "aaaaa";
json.push("aaaaa");
while(lastValue !== json[json.length-1]){
json.push(getNext(5,json[json.length-1]));
}
console.log(json);
}
}
createJSON("aaabz");
You need to use recursive function to generate your keys.
I've written some piece of code in this fiddle link, which generate keys as per your requirement and create JSON too.
Please note I assume small case alphabets keys only. and used 3 length string (aaa), You can use 4 length also but performance degrades.
You can change any first key in input in attached fiddle, like 'aay' then code generate next all possible keys.(aaz, aba,.....,zzz).
You can use this
function getNextKey(lastKeyCode, changeIndex)
{
var charCodes = [];
if( changeIndex == undefined )
changeIndex = lastKeyCode.length - 1;
if(changeIndex - 1 > -1 && lastKeyCode.charCodeAt(changeIndex) == 122 )
{
lastKeyCode = getNextKey(lastKeyCode, changeIndex - 1);
}
lastKeyCode.split('').forEach(function(e){charCodes.push(e.charCodeAt())});
charCodes[changeIndex] = 97 + (charCodes[changeIndex] - 96 ) % 26;
return String.fromCharCode.apply(0, charCodes);
}
//-------------------EDIT ( GENERATE KEYS LIKE THIS )------------
function generateKeys(lastKey)
{
var json = [];
var nextKey = new Array(lastKey.length + 1 ).join('a');
json.push(nextKey);
while( nextKey != lastKey )
{
json.push( (nextKey = getNextKey(nextKey)) )
}
return json;
}
//---------------------------Example----------------------------
var last = 'test';
console.log('Last Key : '+last+' | Generated key length : '+generateKeys(last).length);
i m trying to calculate weight of a string using the following function
function weight(w)
{
Cap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
small = 'abcdefghijklmnopqrstuvwxyz'
spcl = "~!##$%^&*()_+[]\{}|;':,./<>?"
num = '0123456789'
var p = []
for(i=0;i<w.length;i++)
{
if(Cap.contains(w[i])==true)
p[i] = Cap.indexOf(w[i]) + 2
else if(small.contains(w[i])==true)
p[i] = small.indexOf(w[i]) + 1
else if(num.contains(w[i]))
p[i] = num.indexOf(w[i])
else if(spcl.contains(w[i]))
p[i] = 1
}
return _.reduce(p,function(memo, num){ return memo + num; }, 0);
}
where w is a string. this properly calculates weight of the string.
But whn i try to to calculate weight of strings given in a an array, it jst calculates the weight of the first element, ie. it does not run the full for loop. can anyone explain to me why is that so??
the for loop is as given below
function weightList(l)
{
weigh = []
for(i=0;i<l.length;i++)
weigh.push(weight(l[i]));
return weigh;
}
input and output:
>>> q = ['abad','rewfd']
["abad", "rewfd"]
>>> weightList(q)
[8]
whereas the output array should have had 2 entries.
[8,56]
i do not want to use Jquery. i want to use Vanilla only.
Because i is a global variable. So when it goes into the function weight it sets the value of i greater than the lenght of l. Use var, it is not optional.
for(var i=0;i<l.length;i++)
and
for(var i=0;i<w.length;i++)
You should be using var with the other variables in the function and you should be using semicolons.
I think your issue is just malformed JavaScript. Keep in mind that JavaScript sucks, and is not as forgiving as some other languages are.
Just by adding a few "var" and semicolons, I was able to get it to work with what you had.
http://jsfiddle.net/3D5Br/
function weight(w) {
var Cap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
small = 'abcdefghijklmnopqrstuvwxyz',
spcl = "~!##$%^&*()_+[]\{}|;':,./<>?",
num = '0123456789',
p = [];
for(var i=0;i<w.length;i++){
if(Cap.contains(w[i])==true)
p[i] = Cap.indexOf(w[i]) + 2
else if(small.contains(w[i])==true)
p[i] = small.indexOf(w[i]) + 1
else if(num.contains(w[i]))
p[i] = num.indexOf(w[i])
else if(spcl.contains(w[i]))
p[i] = 1
}
return _.reduce(p,function(memo, num){ return memo + num; }, 0);
}
function weightList(l) {
var weigh = [];
for(var i=0;i<l.length;i++)
weigh.push(weight(l[i]));
return weigh;
}
q = ['abad','rewfd'];
results = weightList(q);
Hope that helps
I'm currently working on coderbyte's medium challenge entitled "Permutation Step."
The goal is to take user input, num, and to return the next number greater than num using the same digits So, for example, if user input is 123, then the number 132 should be returned. If user input is 12453, then 12534 should be returned...
Anywho, I have a correct model answer created by someone (probably a genius, cuz this stuff is pretty hard) and I'm trying to figure out how the answer works, line for line by having an example play out (I'm keeping it simple and playing out the function with user input 123).
The answer has 2 functions, but the 1st function used is what I'm currently trying to work out...
The relevant code is:
var PermutationStep1 = function(num) {
var num1 = num.toString();
var ar = [];
//return num1;
if (num1.length < 2) {
return num;
} else {
for(var i = 0; i < num1.length; i++) {
var num2 = num1[i];
var num3 = num1.substr(0,i) + num1.substr(i+1, num1.length -1);
var numAr = PermutationStep1(num3);
for(var j = 0; j < numAr.length; j++) {
ar.push(numAr[j] + num2);
}
}
ar.sort(function(a,b) {return a-b});
return ar;
}
}
Again, I'm trying to work thru this function with the inputted num as 123 (num = 123).
I'm pretty sure that this function should output an array with multiple elements, because the 2nd function merely compares those array elements with the original user input (in our case, 123), and returns the next greatest value.
So in our case, we should probably get an array, named 'ar', returned with a host of 3 digit values. But for some reason, I'm getting an array of 2 digit values. I can't seem to isolate my mistake and where I'm going wrong. Any help with where, specifically, I'm going wrong (whether it be the recursion, the use of substring-method, or the concating of strings together, whatever my problem may be) would be appreciated...
Here's some of my work so far:
PS1(123) / num1 = 123
i = 0;
num2 = (num1[i]) = '1';
num3 = (num1.substr(0, 0) + num1.substr(1, 2)) = ('0' + '23') = '23'
PS1(23)
i = 0;
num2 = '2';
num3 = '3'
PS1(3) -> numAr = 3 (since num1 is less than 2 digits, which is the recursion base case?)
(So take 3 into the 2nd for loop)...
ar.push(numAr[j] + num2) = ar.push('3' + '1') = 31
ar = [31] at this point
And then I go through the initial for-loop a couple more times, where i = 1 and then i = 2, and I eventually get....
ar = [31, 32, 33]...
But I'm thinking I should have something like ar = [131, 132, 133]? I'm not sure where I'm going wrong so please help. Because the answer is correctly spit out by this function, the correct answer being 132.
Note: if you need the 2nd part of the model answer (i.e. the 2nd function), here it is:
var arr = [];
function PermutationStep(num1) {
arr.push(PermutationStep1(num1));
var arrStr = arr.toString();
var arrStrSpl = arrStr.split(",");
//return arrStrSpl;
for(var p = 0; p < arrStrSpl.length; p++) {
if(arrStrSpl[p] > num1) {
return arrStrSpl[p];
}
}
return -1;
}
I'm sorry the first function i posted was under a mathematical logical mistake and i was to overhasty
I thought about it again and now i have the following function which definitley works
function getNextNumber (num)
{
var numberStr=num.toString (), l=numberStr.length, i;
var digits=new Array (), lighterDigits, digitAtWeight;
var weight,lightWeight, lighterDigits_l, value=0;
for (i=l-1;i>-1;i--)
digits.push (parseInt(numberStr.charAt(i)));
lighterDigits=new Array ();
lighterDigits.push (digits[0]);
for (weight=1;weight<l;weight++)
{
digitAtWeight=digits[weight];
lighterDigits_l=lighterDigits.length;
for (lightWeight=0;lightWeight<lighterDigits_l;lightWeight++)
{
if (digitAtWeight<lighterDigits[lightWeight])
{
lighterDigits.unshift (lighterDigits.splice (lightWeight,1,digitAtWeight)[0]);
lighterDigits.reverse ();
digits=lighterDigits.concat (digits.slice (weight+1,l));
for (weight=0;weight>l;weight++)
value+=Math.pow (10,weight)*digits[weight];
return value;
}
}
lighterDigits.push (digitAtWeight);
}
return NaN;
}
okay here is my solution i found it in 20 minutes ;)
//---- num should be a Number Object and not a String
function getNextNumber (num)
{
var numberStr=num.toString (), l=numberStr.length, i;
var digits=new Array (), digitA, digitB;
var weight,lightWeight;
var valueDifference,biggerValue;
for (i=l-1;i>-1;i--)
digits.push (parseInt(numberStr.charAt(i))); // 345 becomes a0=5 a1=4 a2=3 and we can say that num= a0*10^0+ a1*10^1+ a2*10^2, so the index becomes the decimal weight
for (weight=1;weight<l;weight++)
{
digitA=digits[weight];
biggerValue=new Array ();
for (lightWeight=weight-1;lightWeight>-1;lightWeight--)
{
digitB=digits[lightWeight];
if (digitB==digitA) continue;
valueDifference=(digitA-digitB)*(-Math.pow(10,weight)+Math.pow (10,lightWeight));
if (valueDifference>0) biggerValue.push(valueDifference);
}
if (biggerValue.length>0)
{
biggerValue.sort();
return (biggerValue[0]+num);
}
}
}
this is the solution I figured out for the problem without using a recursive function. It's passed all the tests on coderbyte. I am still new to this so using recursion is not the first thing I look for. hope this can help anyone else looking for a solution.
function PermutationStep(num) {
var numArr = (num + '').split('').sort().reverse();
var numJoin = numArr.join('');
for (var i = (num + 1); i <= parseInt(numJoin); i++){
var aaa = (i + '').split('').sort().reverse();
if (aaa.join('') == numJoin){
return i;
}
}
return -1;
}
I am trying to increment a number by a given value each second and retain the formatting using JavaScript or JQuery
I am struggling to do it.
Say I have a number like so:
1412015
the number which this can be incremented by each second is variable it could be anything beween 0.1 and 2.
Is it possible, if the value which it has to be incremented by each second is 0.54 to incremenet the number and have the following output:
1,412,016
1,412,017
1,412,018
Thanks
Eef
I'm not quite sure I understand your incrementation case and what you want to show.
However, I decided to chime in on a solution to format a number.
I've got two versions of a number format routine, one which parses an array, and one which formats with a regular expression. I'll admit they aren't the easiest to read, but I had fun coming up with the approach.
I've tried to describe the lines with comments in case you're curious
Array parsing version:
function formatNum(num) {
//Convert a formatted number to a normal number and split off any
//decimal places if they exist
var parts = String( num ).replace(/[^\d.]-/g,'').split('.');
//turn the string into a character array and reverse
var arr = parts[0].split('').reverse();
//initialize the return value
var str = '';
//As long as the array still has data to process (arr.length is
//anything but 0)
//Use a for loop so that it keeps count of the characters for me
for( var i = 0; arr.length; i++ ) {
//every 4th character that isn't a minus sign add a comma before
//we add the character
if( i && i%3 == 0 && arr[0] != '-' ) {
str = ',' + str ;
}
//add the character to the result
str = arr.shift() + str ;
}
//return the final result appending the previously split decimal place
//if necessary
return str + ( parts[1] ? '.'+parts[1] : '' );
}
Regular Expression version:
function formatNum(num) {
//Turn a formatted number into a normal number and separate the
//decimal places
var parts = String( num ).replace(/[^\d.]-/g,'').split('.');
//reverse the string
var str = parts[0].split('').reverse().join('');
//initialize the return value
var retVal = '';
//This gets complicated. As long as the previous result of the regular
//expression replace is NOT the same as the current replacement,
//keep replacing and adding commas.
while( retVal != (str = str.replace(/(\d{3})(\d{1,3})/,'$1,$2')) ) {
retVal = str;
}
//If there were decimal points return them back with the reversed string
if( parts[1] ) {
return retVal.split('').reverse().join('') + '.' + parts[1];
}
//return the reversed string
return retVal.split('').reverse().join('');
}
Assuming you want to output a formatted number every second incremented by 0.54 you could use an interval to do your incrementation and outputting.
Super Short Firefox with Firebug only example:
var num = 1412015;
setInterval(function(){
//Your 0.54 value... why? I don't know... but I'll run with it.
num += 0.54;
console.log( formatNum( num ) );
},1000);
You can see it all in action here: http://jsbin.com/opoze
To increment a value on every second use this structure:
var number = 0; // put your initial value here
function incrementNumber () {
number += 1; // you can increment by anything you like here
}
// this will run incrementNumber() every second (interval is in ms)
setInterval(incrementNumber, 1000);
This will format numbers for you:
function formatNumber(num) {
num = String(num);
if (num.length <= 3) {
return num;
} else {
var last3nums = num.substring(num.length - 3, num.length);
var remindingPart = num.substring(0, num.length - 3);
return formatNumber(remindingPart) + ',' + last3nums;
}
}
function rounded_inc(x, n) {
return x + Math.ceil(n);
}
var x = 1412015;
x = rounded_inc(x, 0.54);