I need string Double each letter in a string
abc -> aabbcc
i try this
var s = "abc";
for(var i = 0; i < s.length ; i++){
console.log(s+s);
}
o/p
> abcabc
> abcabc
> abcabc
but i need
aabbcc
help me
Use String#split , Array#map and Array#join methods.
var s = "abc";
console.log(
// split the string into individual char array
s.split('').map(function(v) {
// iterate and update
return v + v;
// join the updated array
}).join('')
)
UPDATE : You can even use String#replace method for that.
var s = "abc";
console.log(
// replace each charcter with repetition of it
// inside substituting string you can use $& for getting matched char
s.replace(/./g, '$&$&')
)
You need to reference the specific character at the index within the string with s[i] rather than just s itself.
var s = "abc";
var out = "";
for(var i = 0; i < s.length ; i++){
out = out + (s[i] + s[i]);
}
console.log(out);
I have created a function which takes string as an input and iterate the string and returns the final string with each character doubled.
var s = "abcdef";
function makeDoubles(s){
var s1 = "";
for(var i=0; i<s.length; i++){
s1 += s[i]+s[i];
}
return s1;
}
alert(makeDoubles(s));
if you want to make it with a loop, then you have to print s[i]+s[i];
not, s + s.
var s = "abc";
let newS = "";
for (var i = 0; i < s.length; i++) {
newS += s[i] + s[i];
}
console.log(newS);
that works for me, maybe a little bit hardcoded, but I am new too))
good luck
console.log(s+s);, here s holds entire string. You will have to fetch individual character and append it.
var s = "abc";
var r = ""
for (var i = 0; i < s.length; i++) {
var c = s.charAt(i);
r+= c+c
}
console.log(r)
var doubleStr = function(str) {
str = str.split('');
var i = 0;
while (i < str.length) {
str.splice(i, 0, str[i]);
i += 2;
}
return str.join('');
};
You can simply use one of these two methods:
const doubleChar = (str) => str.split("").map(c => c + c).join("");
OR
function doubleChar(str) {
var word = '';
for (var i = 0; i < str.length; i++){
word = word + str[i] + str[i];
};
return word;
};
function doubleChar(str) {
let sum = [];
for (let i = 0; i < str.length; i++){
let result = (str[i]+str[i]);
sum = sum + result;
}
return sum;
}
console.log (doubleChar ("Hello"));
The code below should reverse all the characters in a sentence, but it is unable to do so. This is child's play to me but at this moment it's not compiling. Can anyone figure out the issue?
Let's say:
"Smart geeks are fast coders".
The below code should reverse the above string as follows:
"trams skeeg era tsaf sredoc"
function solution(S){
var result = false;
if(S.length === 1){
result = S;
}
if(S.length > 1 && S.length < 100){
var wordsArray = S.split(" "),
wordsCount = wordsAray.length,
reverseWordsString = '';
for(var i = 0; i< wordsCount; i++){
if(i > 0){
reverseWordsString = reverseWordsString + ' ';
}
reverseWordsString = reverseWordsString + wordsAray[i].split("").reverse().join("");
}
result = reverseWordsString;
}
return result;
}
This should give you the result you're looking for.
function reverseWords(s) {
return s.replace(/[a-z]+/ig, function(w){return w.split('').reverse().join('')});
}
function reverseWords(s) {
var arr = s.split(" ");
s = '';
for(i = 0; i < arr.length; i++) {
s += arr[i].split('').reverse().join('').toLowerCase() + " ";
}
return s;
}
Wouldn't that do the job for you? Basically it just converts the string into an array, by splitting it on space. Then it loops over the array, adds every string reversed to a new string, and then it converts it to lowercase. For faster speed (nothing you would notice), you can just call newStr.toLowerCase() after the loop, so it will do it once instead of every time.
New to the JavaScript language and need help creating a function which generates the following display.
abcdefghijklmnopqrstuvwxyz
bcdefghijklmnopqrstuvwxyz
cdefghijklmnopqrstuvwxyz
defghijklmnopqrstuvwxyz
.... and so on, all the way down to
xyz
yz
z
I am not asking for handouts, just a little kickstart for a beginner to get started! Links, hints, tips, anything helps! Thanks!
Arrays and loops are powerful when combined.
var alphabet = "abcdefghijklmnopqrstuvwxyz".split('');
console.log(alphabet.join(''));
while (alphabet.length > 0) {
alphabet.shift();
console.log(alphabet.join(''));
}
Edit:
If you really need your decremented alphabet to be left-padded, you can use this:
var alphabet = "abcdefghijklmnopqrstuvwxyz";
var letters = alphabet.split('');
var addPadding = (function (minLength) {
return function (shortString) {
if (shortString.length < minLength) {
return new Array(
minLength - shortString.length + 1
).join(' ') + shortString;
}
};
}(alphabet.length));
console.log(alphabet);
while (letters.length > 0) {
letters.shift();
console.log(addPadding(letters.join('')));
}
Edit:
Here is a much simpler answer:
function decrementingAlphabet () {
var alphabet = 'abcdefghijklmnopqrstuvwxyz';
function iterate(spaces, letters) {
if (letters.length > 0) {
console.log(spaces + letters);
iterate(spaces + ' ', letters.substring(1));
} else {
return;
}
}
iterate('', alphabet);
}
This is simple example.
var str = '';
for (var s=0; s < 26; ++s) {
str = '';
for (var i=0; i < 26 - s; ++i) {
str += String.fromCharCode(97+s+i);
}
document.write(str + "<br/>");
}
See http://jsfiddle.net/G5Gds
Hmm, maybe this will help put you on the right track?
var str = '';
// Find out what 'a' is in ASCII
var baseLetterCode = 'a'.charCodeAt(0);
// Loop once for each letter
for (var i = 0; i < 26; ++i) {
// Append to string
str += String.fromCharCode(baseLetterCode + i);
}
In character codes, small alphabets lie from 97 onwards(97 for a). You need to use 2 for loops to print such series.
Here is your jsfiddle demo:
var display='';
for(var i=97;i<123;i++){
var s='';
for(var j=i;j<123;j++){
s+= String.fromCharCode( j );
}
display+=s;
}
alert(display);
(function() {
var theENalphabet = [];
for (var charNow = "a".charCodeAt(0); charNow <= "z".charCodeAt(0); charNow += 1) {
theENalphabet.push(String.fromCharCode(charNow));
}
var isNow = 0;
function decrAlph(startAt) {
var alphString = "";
for (var i = startAt; i < theENalphabet.length; i += 1) {
alphString += theENalphabet[i];
}
console.log(alphString);
isNow++;
while (isNow < theENalphabet.length) {
decrAlph(startAt + 1);
}
};
decrAlph(0);
})();
The charCode getting could be abstracted into a function:
var getCharCode = function(el){
return String.prototype.charCodeAt.call(el, 0);
};
getCharCode("a"); // returns 97..
I have to make a function in JavaScript that removes all duplicated letters in a string. So far I've been able to do this: If I have the word "anaconda" it shows me as a result "anaconda" when it should show "cod". Here is my code:
function find_unique_characters( string ){
var unique='';
for(var i=0; i<string.length; i++){
if(unique.indexOf(string[i])==-1){
unique += string[i];
}
}
return unique;
}
console.log(find_unique_characters('baraban'));
We can also now clean things up using filter method:
function removeDuplicateCharacters(string) {
return string
.split('')
.filter(function(item, pos, self) {
return self.indexOf(item) == pos;
})
.join('');
}
console.log(removeDuplicateCharacters('baraban'));
Working example:
function find_unique_characters(str) {
var unique = '';
for (var i = 0; i < str.length; i++) {
if (str.lastIndexOf(str[i]) == str.indexOf(str[i])) {
unique += str[i];
}
}
return unique;
}
console.log(find_unique_characters('baraban'));
console.log(find_unique_characters('anaconda'));
If you only want to return characters that appear occur once in a string, check if their last occurrence is at the same position as their first occurrence.
Your code was returning all characters in the string at least once, instead of only returning characters that occur no more than once. but obviously you know that already, otherwise there wouldn't be a question ;-)
Just wanted to add my solution for fun:
function removeDoubles(string) {
var mapping = {};
var newString = '';
for (var i = 0; i < string.length; i++) {
if (!(string[i] in mapping)) {
newString += string[i];
mapping[string[i]] = true;
}
}
return newString;
}
With lodash:
_.uniq('baraban').join(''); // returns 'barn'
You can put character as parameter which want to remove as unique like this
function find_unique_characters(str, char){
return [...new Set(str.split(char))].join(char);
}
function find_unique_characters(str, char){
return [...new Set(str.split(char))].join(char);
}
let result = find_unique_characters("aaaha ok yet?", "a");
console.log(result);
//One simple way to remove redundecy of Char in String
var char = "aaavsvvssff"; //Input string
var rst=char.charAt(0);
for(var i=1;i<char.length;i++){
var isExist = rst.search(char.charAt(i));
isExist >=0 ?0:(rst += char.charAt(i) );
}
console.log(JSON.stringify(rst)); //output string : avsf
For strings (in one line)
removeDuplicatesStr = str => [...new Set(str)].join('');
For arrays (in one line)
removeDuplicatesArr = arr => [...new Set(arr)]
Using Set:
removeDuplicates = str => [...new Set(str)].join('');
Thanks to David comment below.
DEMO
function find_unique_characters( string ){
unique=[];
while(string.length>0){
var char = string.charAt(0);
var re = new RegExp(char,"g");
if (string.match(re).length===1) unique.push(char);
string=string.replace(re,"");
}
return unique.join("");
}
console.log(find_unique_characters('baraban')); // rn
console.log(find_unique_characters('anaconda')); //cod
var str = 'anaconda'.split('');
var rmDup = str.filter(function(val, i, str){
return str.lastIndexOf(val) === str.indexOf(val);
});
console.log(rmDup); //prints ["c", "o", "d"]
Please verify here: https://jsfiddle.net/jmgy8eg9/1/
Using Set() and destructuring twice is shorter:
const str = 'aaaaaaaabbbbbbbbbbbbbcdeeeeefggggg';
const unique = [...new Set([...str])].join('');
console.log(unique);
Yet another way to remove all letters that appear more than once:
function find_unique_characters( string ) {
var mapping = {};
for(var i = 0; i < string.length; i++) {
var letter = string[i].toString();
mapping[letter] = mapping[letter] + 1 || 1;
}
var unique = '';
for (var letter in mapping) {
if (mapping[letter] === 1)
unique += letter;
}
return unique;
}
Live test case.
Explanation: you loop once over all the characters in the string, mapping each character to the amount of times it occurred in the string. Then you iterate over the items (letters that appeared in the string) and pick only those which appeared only once.
function removeDup(str) {
var arOut = [];
for (var i=0; i < str.length; i++) {
var c = str.charAt(i);
if (c === '_') continue;
if (str.indexOf(c, i+1) === -1) {
arOut.push(c);
}
else {
var rx = new RegExp(c, "g");
str = str.replace(rx, '_');
}
}
return arOut.join('');
}
I have FF/Chrome, on which this works:
var h={};
"anaconda".split("").
map(function(c){h[c] |= 0; h[c]++; return c}).
filter(function(c){return h[c] == 1}).
join("")
Which you can reuse if you write a function like:
function nonRepeaters(s) {
var h={};
return s.split("").
map(function(c){h[c] |= 0; h[c]++; return c}).
filter(function(c){return h[c] == 1}).
join("");
}
For older browsers that lack map, filter etc, I'm guessing that it could be emulated by jQuery or prototype...
This code worked for me on removing duplicate(repeated) characters from a string (even if its words separated by space)
Link: Working Sample JSFiddle
/* This assumes you have trim the string and checked if it empty */
function RemoveDuplicateChars(str) {
var curr_index = 0;
var curr_char;
var strSplit;
var found_first;
while (curr_char != '') {
curr_char = str.charAt(curr_index);
/* Ignore spaces */
if (curr_char == ' ') {
curr_index++;
continue;
}
strSplit = str.split('');
found_first = false;
for (var i=0;i<strSplit.length;i++) {
if(str.charAt(i) == curr_char && !found_first)
found_first = true;
else if (str.charAt(i) == curr_char && found_first) {
/* Remove it from the string */
str = setCharAt(str,i,'');
}
}
curr_index++;
}
return str;
}
function setCharAt(str,index,chr) {
if(index > str.length-1) return str;
return str.substr(0,index) + chr + str.substr(index+1);
}
Here's what I used - haven't tested it for spaces or special characters, but should work fine for pure strings:
function uniquereduce(instring){
outstring = ''
instringarray = instring.split('')
used = {}
for (var i = 0; i < instringarray.length; i++) {
if(!used[instringarray[i]]){
used[instringarray[i]] = true
outstring += instringarray[i]
}
}
return outstring
}
Just came across a similar issue (finding the duplicates). Essentially, use a hash to keep track of the character occurrence counts, and build a new string with the "one-hit wonders":
function oneHitWonders(input) {
var a = input.split('');
var l = a.length;
var i = 0;
var h = {};
var r = "";
while (i < l) {
h[a[i]] = (h[a[i]] || 0) + 1;
i += 1;
}
for (var c in h) {
if (h[c] === 1) {
r += c;
}
}
return r;
}
Usage:
var a = "anaconda";
var b = oneHitWonders(a); // b === "cod"
Try this code, it works :)
var str="anaconda";
Array.prototype.map.call(str,
(obj,i)=>{
if(str.indexOf(obj,i+1)==-1 && str.lastIndexOf(obj,i-1)==-1){
return obj;
}
}
).join("");
//output: "cod"
This should work using Regex ;
NOTE: Actually, i dont know how this regex works ,but i knew its 'shorthand' ,
so,i would have Explain to you better about meaning of this /(.+)(?=.*?\1)/g;.
this regex only return to me the duplicated character in an array ,so i looped through it to got the length of the repeated characters .but this does not work for a special characters like "#" "_" "-", but its give you expected result ; including those special characters if any
function removeDuplicates(str){
var REPEATED_CHARS_REGEX = /(.+)(?=.*?\1)/g;
var res = str.match(REPEATED_CHARS_REGEX);
var word = res.slice(0,1);
var raw = res.slice(1);
var together = new String (word+raw);
var fer = together.toString();
var length = fer.length;
// my sorted duplicate;
var result = '';
for(var i = 0; i < str.length; i++) {
if(result.indexOf(str[i]) < 0) {
result += str[i];
}
}
return {uniques: result,duplicates: length};
} removeDuplicates('anaconda')
The regular expression /([a-zA-Z])\1+$/ is looking for:
([a-zA-Z]]) - A letter which it captures in the first group; then
\1+ - immediately following it one or more copies of that letter; then
$ - the end of the string.
Changing it to /([a-zA-Z]).*?\1/ instead searches for:
([a-zA-Z]) - A letter which it captures in the first group; then
.*? - zero or more characters (the ? denotes as few as possible); until
\1 - it finds a repeat of the first matched character.
I have 3 loopless, one-line approaches to this.
Approach 1 - removes duplicates, and preserves original character order:
var str = "anaconda";
var newstr = str.replace(new RegExp("[^"+str.split("").sort().join("").replace(/(.)\1+/g, "").replace(/[.?*+^$[\]\\(){}|-]/g, "\\$&")+"]","g"),"");
//cod
Approach 2 - removes duplicates but does NOT preserve character order, but may be faster than Approach 1 because it uses less Regular Expressions:
var str = "anaconda";
var newstr = str.split("").sort().join("").replace(/(.)\1+/g, "");
//cdo
Approach 3 - removes duplicates, but keeps the unique values (also does not preserve character order):
var str = "anaconda";
var newstr = str.split("").sort().join("").replace(/(.)(?=.*\1)/g, "");
//acdno
function removeduplicate(str) {
let map = new Map();
// n
for (let i = 0; i < str.length; i++) {
if (map.has(str[i])) {
map.set(str[i], map.get(str[i]) + 1);
} else {
map.set(str[i], 1);
}
}
let res = '';
for (let i = 0; i < str.length; i++) {
if (map.get(str[i]) === 1) {
res += str[i];
}
}
// o (2n) - > O(n)
// space o(n)
return res;
}
If you want your function to just return you a unique set of characters in your argument, this piece of code might come in handy.
Here, you can also check for non-unique values which are being recorded in 'nonUnique' titled array:
function remDups(str){
if(!str.length)
return '';
var obj = {};
var unique = [];
var notUnique = [];
for(var i = 0; i < str.length; i++){
obj[str[i]] = (obj[str[i]] || 0) + 1;
}
Object.keys(obj).filter(function(el,ind){
if(obj[el] === 1){
unique+=el;
}
else if(obj[el] > 1){
notUnique+=el;
}
});
return unique;
}
console.log(remDups('anaconda')); //prints 'cod'
If you want to return the set of characters with their just one-time occurrences in the passed string, following piece of code might come in handy:
function remDups(str){
if(!str.length)
return '';
var s = str.split('');
var obj = {};
for(var i = 0; i < s.length; i++){
obj[s[i]] = (obj[s[i]] || 0) + 1;
}
return Object.keys(obj).join('');
}
console.log(remDups('anaconda')); //prints 'ancod'
function removeDuplicates(str) {
var result = "";
var freq = {};
for(i=0;i<str.length;i++){
let char = str[i];
if(freq[char]) {
freq[char]++;
} else {
freq[char] =1
result +=char;
}
}
return result;
}
console.log(("anaconda").split('').sort().join('').replace(/(.)\1+/g, ""));
By this, you can do it in one line.
output: 'cdo'
function removeDuplicates(string){
return string.split('').filter((item, pos, self)=> self.indexOf(item) == pos).join('');
}
the filter will remove all characters has seen before using the index of item and position of the current element
Method 1 : one Simple way with just includes JS- function
var data = 'sssssddddddddddfffffff';
var ary = [];
var item = '';
for (const index in data) {
if (!ary.includes(data[index])) {
ary[index] = data[index];
item += data[index];
}
}
console.log(item);
Method 2 : Yes we can make this possible without using JavaScript function :
var name = 'sssssddddddddddfffffff';
let i = 0;
let newarry = [];
for (let singlestr of name) {
newarry[i] = singlestr;
i++;
}
// now we have new Array and length of string
length = i;
function getLocation(recArray, item, arrayLength) {
firstLaction = -1;
for (let i = 0; i < arrayLength; i++) {
if (recArray[i] === item) {
firstLaction = i;
break;
}
}
return firstLaction;
}
let finalString = '';
for (let b = 0; b < length; b++) {
const result = getLocation(newarry, newarry[b], length);
if (result === b) {
finalString += newarry[b];
}
}
console.log(finalString); // sdf
// Try this way
const str = 'anaconda';
const printUniqueChar = str => {
const strArr = str.split("");
const uniqueArray = strArr.filter(el => {
return strArr.indexOf(el) === strArr.lastIndexOf(el);
});
return uniqueArray.join("");
};
console.log(printUniqueChar(str)); // output-> cod
function RemDuplchar(str)
{
var index={},uniq='',i=0;
while(i<str.length)
{
if (!index[str[i]])
{
index[str[i]]=true;
uniq=uniq+str[i];
}
i++;
}
return uniq;
}
We can remove the duplicate or similar elements in string using for loop and extracting string methods like slice, substring, substr
Example if you want to remove duplicate elements such as aababbafabbb:
var data = document.getElementById("id").value
for(var i = 0; i < data.length; i++)
{
for(var j = i + 1; j < data.length; j++)
{
if(data.charAt(i)==data.charAt(j))
{
data = data.substring(0, j) + data.substring(j + 1);
j = j - 1;
console.log(data);
}
}
}
Please let me know if you want some additional information.
How do I break up a string every X amount of characters? For example, I'd like to break up a very long string every 1000 characters, and the string could be completely random everytime.
var string = <my text string that is thousands of characters long>
You could use Regex:
'asdfasdfasdfasdf'.match(/.{3}|.{1,2}/g); // 'asd', 'fas', etc.
Replace 3 with 1000 of course.
Here's a contrived example: http://jsfiddle.net/ReRPz/1/
As a function:
function splitInto(str, len) {
var regex = new RegExp('.{' + len + '}|.{1,' + Number(len-1) + '}', 'g');
return str.match(regex );
}
That RegExp really only needs to be created once if you have a set number to split like 1000.
Try this function:
function getParts(str, len)
{
var res = [];
while (str.length) {
res.push(str.substring(0, len));
str = str.substring(len);
}
return res;
}
var s = "qweasedzxcqweasdxzc12";
console.log(getParts(s, 10));
i would use substring function on string
str = //the given string
arr = [];
for(i=0;i<str.length;i+=1000)
{
s = i;
// if the last string is less than 1000chars
e = (str.length - i) > 1000 ? (i+1000) : (str.length - i);
arr.push = str.substring(s,e);
}
Here's a way to do it recursively:
var string = "my text string that is thousands of characters long";
var arr = [];
function div( str, len ) {
if( str.length < len )
return arr.push(str);
else
arr.push(str.substring(0,len))
div( str.substring(len), len );
}
div( string, 5 );
for( var i = 0; i < arr.length; i++ ) {
document.write( arr[i] + "<br/>");
}
/* output:
my te
xt st
ring
that
is th
ousan
ds of
char
acter
s lon
g
*/
Like this:
var myString = "my text string that is thousands of characters long";
var myCurrentString = "";
var myBrokenUpString = new Array();
for(var i = 0; i < myString.length; i++) {
myCurrentString += myString.charAt(i);
if(i % 1000 == 0) {
myBrokenUpString.push(myCurrentString);
myCurrentString = "";
}
if(i + 1 == myString.length) myBrokenUpString.push(myCurrentString);
}
Please note that the above code is untested and may contain errors.
You can then POST the array and piece it back together on the other end. The piecing-together-code would look something like this:
var myRestoredString = "";
for(var i = 0; i<myBrokenUpString.length; i++) {
myRestoredString += myBrokenUpString[i];
}
Borrowing the idea from Joe Tuskan:
var str = 'asdfasdfasdfasdf';
var len = 3;
var regex = new RegExp(".{"+len+"}", "g");
var trail = str.length - (str.length % len);
var parts = str.match(regex);
parts.push(str.substring(trail));
document.write(parts.join('<br>'));
http://jsfiddle.net/6aSHB/1/