Develop Reference

How can I extract all contained characters in a String? [duplicate]

I have a string with repeated letters. I want letters that are repeated more than once to show only once.
Example input: aaabbbccc
Expected output: abc
I've tried to create the code myself, but so far my function has the following problems:
if the letter doesn't repeat, it's not shown (it should be)
if it's repeated once, it's show only once (i.e. aa shows a - correct)
if it's repeated twice, shows all (i.e. aaa shows aaa - should be a)
if it's repeated 3 times, it shows 6 (if aaaa it shows aaaaaa - should be a)
function unique_char(string) {
var unique = '';
var count = 0;
for (var i = 0; i < string.length; i++) {
for (var j = i+1; j < string.length; j++) {
if (string[i] == string[j]) {
count++;
unique += string[i];
}
}
}
return unique;
}
document.write(unique_char('aaabbbccc'));
The function must be with loop inside a loop; that's why the second for is inside the first.

Fill a Set with the characters and concatenate its unique entries:
function unique(str) {
return String.prototype.concat.call(...new Set(str));
}
console.log(unique('abc')); // "abc"
console.log(unique('abcabc')); // "abc"

Convert it to an array first, then use Josh Mc’s answer at How to get unique values in an array, and rejoin, like so:
var nonUnique = "ababdefegg";
var unique = Array.from(nonUnique).filter(function(item, i, ar){ return ar.indexOf(item) === i; }).join('');
All in one line. :-)

Too late may be but still my version of answer to this post:
function extractUniqCharacters(str){
var temp = {};
for(var oindex=0;oindex<str.length;oindex++){
temp[str.charAt(oindex)] = 0; //Assign any value
}
return Object.keys(temp).join("");
}

You can use a regular expression with a custom replacement function:
function unique_char(string) {
return string.replace(/(.)\1*/g, function(sequence, char) {
if (sequence.length == 1) // if the letter doesn't repeat
return ""; // its not shown
if (sequence.length == 2) // if its repeated once
return char; // its show only once (if aa shows a)
if (sequence.length == 3) // if its repeated twice
return sequence; // shows all(if aaa shows aaa)
if (sequence.length == 4) // if its repeated 3 times
return Array(7).join(char); // it shows 6( if aaaa shows aaaaaa)
// else ???
return sequence;
});
}

Using lodash:
_.uniq('aaabbbccc').join(''); // gives 'abc'

Per the actual question: "if the letter doesn't repeat its not shown"
function unique_char(str)
{
var obj = new Object();
for (var i = 0; i < str.length; i++)
{
var chr = str[i];
if (chr in obj)
{
obj[chr] += 1;
}
else
{
obj[chr] = 1;
}
}
var multiples = [];
for (key in obj)
{
// Remove this test if you just want unique chars
// But still keep the multiples.push(key)
if (obj[key] > 1)
{
multiples.push(key);
}
}
return multiples.join("");
}
var str = "aaabbbccc";
document.write(unique_char(str));

Your problem is that you are adding to unique every time you find the character in string. Really you should probably do something like this (since you specified the answer must be a nested for loop):
function unique_char(string){
var str_length=string.length;
var unique='';
for(var i=0; i<str_length; i++){
var foundIt = false;
for(var j=0; j<unique.length; j++){
if(string[i]==unique[j]){
foundIt = true;
break;
}
}
if(!foundIt){
unique+=string[i];
}
}
return unique;
}
document.write( unique_char('aaabbbccc'))
In this we only add the character found in string to unique if it isn't already there. This is really not an efficient way to do this at all ... but based on your requirements it should work.
I can't run this since I don't have anything handy to run JavaScript in ... but the theory in this method should work.

Try this if duplicate characters have to be displayed once, i.e.,
for i/p: aaabbbccc o/p: abc
var str="aaabbbccc";
Array.prototype.map.call(str,
(obj,i)=>{
if(str.indexOf(obj,i+1)==-1 ){
return obj;
}
}
).join("");
//output: "abc"
And try this if only unique characters(String Bombarding Algo) have to be displayed, add another "and" condition to remove the characters which came more than once and display only unique characters, i.e.,
for i/p: aabbbkaha o/p: kh
var str="aabbbkaha";
Array.prototype.map.call(str,
(obj,i)=>{
if(str.indexOf(obj,i+1)==-1 && str.lastIndexOf(obj,i-1)==-1){ // another and condition
return obj;
}
}
).join("");
//output: "kh"

<script>
uniqueString = "";
alert("Displays the number of a specific character in user entered string and then finds the number of unique characters:");
function countChar(testString, lookFor) {
var charCounter = 0;
document.write("Looking at this string:<br>");
for (pos = 0; pos < testString.length; pos++) {
if (testString.charAt(pos) == lookFor) {
charCounter += 1;
document.write("<B>" + lookFor + "</B>");
} else
document.write(testString.charAt(pos));
}
document.write("<br><br>");
return charCounter;
}
function findNumberOfUniqueChar(testString) {
var numChar = 0,
uniqueChar = 0;
for (pos = 0; pos < testString.length; pos++) {
var newLookFor = "";
for (pos2 = 0; pos2 <= pos; pos2++) {
if (testString.charAt(pos) == testString.charAt(pos2)) {
numChar += 1;
}
}
if (numChar == 1) {
uniqueChar += 1;
uniqueString = uniqueString + " " + testString.charAt(pos)
}
numChar = 0;
}
return uniqueChar;
}
var testString = prompt("Give me a string of characters to check", "");
var lookFor = "startvalue";
while (lookFor.length > 1) {
if (lookFor != "startvalue")
alert("Please select only one character");
lookFor = prompt(testString + "\n\nWhat should character should I look for?", "");
}
document.write("I found " + countChar(testString, lookFor) + " of the<b> " + lookFor + "</B> character");
document.write("<br><br>I counted the following " + findNumberOfUniqueChar(testString) + " unique character(s):");
document.write("<br>" + uniqueString)
</script>

Here is the simplest function to do that
function remove(text)
{
var unique= "";
for(var i = 0; i < text.length; i++)
{
if(unique.indexOf(text.charAt(i)) < 0)
{
unique += text.charAt(i);
}
}
return unique;
}

The one line solution will be to use Set. const chars = [...new Set(s.split(''))];

If you want to return values in an array, you can use this function below.
const getUniqueChar = (str) => Array.from(str)
.filter((item, index, arr) => arr.slice(index + 1).indexOf(item) === -1);
console.log(getUniqueChar("aaabbbccc"));
Alternatively, you can use the Set constructor.
const getUniqueChar = (str) => new Set(str);
console.log(getUniqueChar("aaabbbccc"));

Here is the simplest function to do that pt. 2
const showUniqChars = (text) => {
let uniqChars = "";
for (const char of text) {
if (!uniqChars.includes(char))
uniqChars += char;
}
return uniqChars;
};

const countUnique = (s1, s2) => new Set(s1 + s2).size
a shorter way based on #le_m answer

let unique=myArray.filter((item,index,array)=>array.indexOf(item)===index)

How to maintain case and ignore spaces in Vigenere Cipher

I need to be able to keep the same case, i.e. "Attack" will be "Lxfopv", with the key "lemon". In addition, I need to keep any spaces within the message to be encrypted.
I used an if statement to check for whitespace
if(text.charAt(i) == ' '){
continue;
but it doesn't seem to do anything.
function encrypt(text, key) {
var output= '';
var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
for(var i = 0; i < text.length; i++){
var a= alphabet.indexOf(key.charAt(i % key.length));
var b= alphabet.indexOf(text.charAt(i));
if(text.charAt(i) == ' '){
continue;
}else{
output += alphabet.charAt((a+ b) % alphabet.length);
}
}
return output;
}
if pass in "Attack at Dawn", my desired output should be Lxfopv ef Rnhr but I am recieving LxFopvmHOeIB with the key "lemon".
How can I fix this to get the desired output? Is it something to do with the fact that I have hardcoded my alphabet?

In order to keep the case, you will have to work your transformation on a single case.
Only at the time of adding it to your output, will you convert it to the correct case.
And in order to get the same value than other algorithms which do ignore the space character, you have to use a second iterator variable.
This iterator should get incremented only on valid inputs, and will be used to iterate the key.
inp.oninput = e => log.textContent = encrypt(inp.value, 'lemon');
function encrypt(text, key) {
var output= '';
// single case dictionary
var alphabet = "abcdefghijklmnopqrstuvwxyz";
var low = text.toLowerCase(); // we'll work on this one
for(let i = 0, j = 0; i < text.length; i++){
// here we use `j` for the key
let a = alphabet.indexOf(key.charAt(j % key.length));
let b = alphabet.indexOf(low.charAt(i));
let out = ''; // the character we'll add
if(low.charAt(i) == ' '){
out = ' '; // keep spaces untouched
}else if(b > -1){ // only if valid
out = alphabet.charAt((a+ b) % alphabet.length); // get the ciphered value
j++; // only here we increment `j`
}
if(low[i] !== text[i]) { // if input and lower case are different
// that means that input was upper case
out = out.toUpperCase();
}
output += out;
}
return output;
}
<input id="inp"> <pre id="log"></pre>

Just add the space to your alphabet:
if(text.charAt(i) == ' '){
output += " ";
}

Any alternative way of using this .length & .split()?

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'));

textarea duplicate string check ignoring leading and trailing whitespace

Users will enter various serials in a textarea. Each newline will indicate a new serial. Some requirements/restrictions:
Leading and trailing white spaces are not allowed.
White space within a serial is okay.
Blank serials are not allowed
I'd prefer to not use JQuery.
Store duplicates so they can be shown to the user.
Based on my tests I have a working solution. I want to make sure I'm not missing or overlooking anything. My questions are:
Is there a more efficient ways to check for duplicates?
Are there any glaring test cases that my solution won't catch?
Working Example: http://jsbin.com/ivusuj/1/
function duplicateCheck() {
var output = document.getElementById('Output');
output.innerHTML = '';
var duplicateSerials = [];
var count = 0;
var textArea = document.getElementById('Serials');
var serials = textArea.value.trim().split(/ *\n */);
for(var i = 0;i < serials.length;i++){
var serial = serials[i];
if(serials.indexOf(serial) != serials.lastIndexOf(serial) &&
duplicateSerials.indexOf(serial) == -1 && serial !== '') {
duplicateSerials.push(serial);
}
}
// For testing
output.innerHTML = '<pre>Serials:\t' + serials.toString() + "<br />" +
'Duplicates:\t' + duplicateSerials.toString() + "<br>" +
'</pre>';
}
Note: the above is for a client side check. The same check will be performed server side as well to ensure the data is valid.
Update
Solution comparison: http://jsbin.com/ivusuj/4/edit

I put together a jsfiddle her: http://jsfiddle.net/wrexroad/yFJjR/3/
Actually checking for duplicates that way is pretty inefficient.
Instead of checking for duplicates, this just adds a property to an object where the property's name is is the serial. Then it prints out all of the property names.
This way if you have duplicates, it will just create the property, then overwrite it.
Here is the function:
function duplicateCheck() {
var output = document.getElementById('Output');
output.innerHTML = '';
var textArea = document.getElementById('Serials');
var inputSerials =
textArea.value.trim().split(/ *\n */);
var outputSerials = new Object();
for(var i = 0;i < inputSerials.length;i++){
var serial = inputSerials[i];
//build an object whose properties are serials
//if the serial exists, incremint a counter
if(outputSerials[serial]){
outputSerials[serial]++;
}else{
outputSerials[serial] = 1;
}
}
output.innerHTML =
'Serials: <br />';
for(var i in outputSerials){
output.innerHTML += i + " ";
}
output.innerHTML +=
'<br /><br />Duplicate Serials: <br />';
for(var i in outputSerials){
//check to see if we have any duplicates
if(outputSerials[i] > 1){
output.innerHTML += i + " ";
}
}
}

I think you'd get significantly better performance if you used an object to determine which serials you'd seen before. Something closer to this:
var seen = {};
for (var i = 0, j = serials.length; i < j; ++i) {
var serial = serials[i];
if (seen.hasOwnProperty(serial)) {
// Dupe code goes here.
continue;
}
// Can't be a duplicate if we get to this point.
}
Though that won't work with serials that use periods.

Here's a solution to filter out duplicates.
function formatInput() {
var arrUnique = [], dups = [],
str = document.getElementById('Serials').value
.replace(/\r\n?/g,'\n')
// normalize newlines - not sure what PC's
// return. Mac's are using \n's
.replace(/(^((?!\n)\s)+|((?!\n)\s)+$)/gm,'')
// trim each line
.replace(/^\n+|\n+$|\n+(?=\n(?!\n))/g,''),
// delete empty lines and trim the whole string
arr = str.length ? str.split(/\n/) : [];
// split each line, if any
for (var i = 0; i < arr.length; i++) {
if (arrUnique.indexOf(arr[i]) == -1)
arrUnique.push(arr[i]);
else dups.push(arr[i]);
}
//document.getElementById('Serials').value = arrUnique.join('\n');
console.log('serials:', arr);
console.log('unique:', arrUnique);
console.log('duplicates:', dups);
}

JavaScript - Need help with string manipulation

say you have:
var foo = "donut [$25]"
What would you need to do in order to delete everything between and including the [ ].
so you get: foo = "donut" after the code is run.
So far I have tried most of the solutions below, but they all either do nothing or crash.
Maybe it's something with my code, please see below:
$('select').change(function () { OnSuccess(mydata); });
function OnSuccess(data) {
var total = 0;
$('select').each(function () {
var sov = parseInt($(this).find('option:selected').attr('value')) || 0; //Selected option value
var sop; //Selected Option Price
for (i = 0; i <= data.length; i++) {
if (data[i].partid == sov) {
sop = data[i].price;
total += sop;
$('#totalprice').html(total);
break;
}
};
//debugger;
$(this).find('option').each(function () {
// $(this).append('<span></span>');
var uov = parseInt($(this).attr('value')) || 0; //Unselected option value
var uop; //Unselected Option Price
for (d = 0; d <= data.length; d++) {
if (data[d].partid == uov) {
uop = data[d].price;
break;
}
}
//debugger;
var newtext = uop - sop;
//{ newtext = "" };
//if (newtext = 0) { newtext.toString; newtext = ""; };
//debugger;
var xtext = $(this).text().toString();
//if (xtext.match(/\[.*\]/) != null) {
xtext.replace(/\s*\[[\s\S]*?\]\s*/g, '').trim();
//}
// var temp = xtext.split('[')[0];
// var temp2 = xtext.split(']')[1];
// resultx = temp + temp2;
if (newtext != 0) {
//xtext.replace(/[.*?]/, "");
$(this).attr("text", xtext + " " + "[" + "$" + newtext + "]");
};
});
});
};

You can also use a regular expression, as Jon Martin pointed out:
var yum = "donut[$25]";
yum.replace(/[.*?]/, ""); // returns "donut"

Alternatively:
var temp = foo.split('[')[0];
var temp2 = foo.split(']')[1];
foo = temp + temp2;

You can use regular expressions (the RegExp() object) to match strings.
var foo = "donut[$25]";
foo.match(/\[.*\]/);
The above will return an array of every item in [square brackets], in this case ["[$25]"].
To just get one result as a string, specify the first index like so:
foo.match(/\[.*\]/)[0];
The above will return "[$25]"
Edit: You know what? I completely misread which bit of the string you're after. This is what you're after:
var foo = "donut[$25]";
foo.match(/\w*/)[0];

How about simply;
var yum = "donut[$25]";
print( yum.substr(0, yum.indexOf("[")) );
>>donut

var begin = foo.search("[");
var end = foo.search("]");
var result = foo.substr(0, begin) + foo.substr(end+1); //Combine anything before [ and after ]
Should be ok right?

Your question leaves unspecified the treatment of the spaces before the [ character, anything after the ], will your string ever contain a linefeed character, multiple occurrences of [..], leading or trailing spaces.
The following will replace all occurrences of 'spaces [ ... ] spaces' with a single space, then it trims the result to remove any leading/trailing spaces.
v.replace (/\s*\[[\s\S]*?\]\s*/g, ' ').trim ();