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Javascript replace multiple chars at once

Here is my array and string:
var array = new Array('üÜ', 'ıI', 'iİ', 'ğĞ', 'şŞ', 'çÇ');
var string = 'İSTANBUL, ÜSKÜDAR, Çarşamba'
I'd to replace every (for ü) to [üÜ]. I mean [üÜ]SK[üÜ]DAR. Can anyone help me?

You can use replace() method
string.replace(/ü|Ü/g, '[üÜ]')
For all matches,
array.forEach(function(key){
string = string.replace(new RegExp('['+ key +']', 'g'), '['+ key +']');
});

function replaceAll(source, search, replace, ignoreCase) {
//SCAPE SPECIAL CHARACTERES.
var search1 = search.toString().replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
//IGNORE CASE SENSIVITY.
var ignore = (ignoreCase) ? "gi" : "g";
var result = source.replace(new RegExp(search1, ignore), replace);
return result;
}
var array = new Array('üÜ', 'ıI', 'iİ', 'ğĞ', 'şŞ', 'çÇ');
for (var i=0; i < array.length; i++){
array[i] = replaceAll(array[i],"ü", "üÜ",true);
}

Reversing words in a string JS without using built in function

Without using the split reverse and join functions, how would one do such a thing?
The Problem Given: Reverse the words in a string
Sample Input: "Hello World"
Sample Output: "World Hello"
<script>
var newString = "";
var theString = prompt("Enter a Phrase that you would like to reverse (Ex. Hello world)");
newString = theString.split(" ").reverse().join(" ")
document.write(newString);
</script>

Arrays can be used like stacks out of the box. And stacks are LIFO, which is what you need.
function reverseWords(str) {
var word, words, reverse;
words = str.match(/(?:\w+)/g);
reverse = '';
while(word = words.pop()) {
reverse += word + ' ';
}
return reverse.trim();
}
reverseWords('hello world');
Or use the call stack as your stack:
function reverseWords(str) {
var result = '';
(function readWord(i = 0) {
var word = '';
if(i > str.length) {
return '';
}
while(str[i] !== ' ' && i < str.length) {
word += str[i];
i++;
}
readWord(++i); // Skip over delimiter.
result += word + ' ';
}());
return result.trim();
}
reverseWords('hello world');

Another idea for reversing the words in a String is using a Stack data structure. Like so:
var newString = "";
var theString = prompt("Enter a Phrase that you would like to reverse (Ex. Hello world)");
var word = "";
var c;
var stack = [];
for (var i = 0, len = theString.length; i < len; i++) {
c = theString[i];
word += c;
if (c == " " || i == (len-1)) {
word = word.trim();
stack.push(word);
word = "";
}
}
while (s = stack.pop()) {
newString += s + " ";
}
console.log(newString);

You could also go fancy and try something like this:
I couldn't come up with a shorter solution.
var newString = "";
var theString = prompt("Enter a Phrase that you would like to reverse (Ex. Hello world)");
theString.replace(/[^\s]*/g, function (value) {
newString = value + ' ' + newString;
});
document.write(newString);

Of the millions of different solutions, the least amount of typing I could come up with involves using lastIndexOf and substring.
var str = "The quick brown fox",
reversed = "",
idx;
while(true) {
idx = str.lastIndexOf(" ")
reversed = reversed + str.substring(idx).trim() + " "
if (idx < 0) break;
str = str.substring(0, idx)
}
reversed.trim() # Oh, yes, trim too
Output:
"fox brown quick The"

The simplest way to do in javascript. Here replace() have /,/g it will replace all comma from the string to space.
var msg = 'Hello world I am Programmer';
var newstr = msg.split(" ").reverse().join().replace(/,/g, ' ');
console.log(newstr)
;

Replacing commas with dot and dot with commas

I am trying to replace all dots for comma and commas for dots and was wondering what is the best practice for doing this. If I do it sequentially, then the steps will overwrite each other.
For example:
1,234.56 (after replacing commas) --> 1.234.56 (after replacing dots) --> 1,234,56
Which is obviously not what I want.
One option I guess is splitting on the characters and joining afterwards using the opposite character. Is there an easier/better way to do this?

You could use a callback
"1,234.56".replace(/[.,]/g, function(x) {
return x == ',' ? '.' : ',';
});
FIDDLE
If you're going to replace more than two characters, you could create a convenience function using a map to do the replacements
function swap(str, swaps) {
var reg = new RegExp('['+Object.keys(swaps).join('')+']','g');
return str.replace(reg, function(x) { return swaps[x] });
}
var map = {
'.':',',
',':'.'
}
var result = swap("1,234.56", map); // 1.234,56
FIDDLE

You could do the following:
var str = '1,234.56';
var map = {',':'.','.':','};
str = str.replace(/[,.]/g, function(k) {
return map[k];
});
Working Demo

Do it in stages using placeholder text:
var foo = '1,234.56';
foo = foo
.replace(',', '~comma~')
.replace('.', '~dot~')
.replace('~comma~', '.')
.replace('~dot~', ',')

You could use a for loop. Something like:
var txt = document.getElementById("txt");
var newStr = "";
for (var i = 0; i < txt.innerHTML.length; i++){
var char = txt.innerHTML.charAt(i);
if (char == "."){
char = ",";
}else if (char == ","){
char = ".";
}
newStr += char;
}
txt.innerHTML = newStr;
Here's a fiddle:
http://jsfiddle.net/AyLQt/1/
Have to say though, #adenoeo's answer is way more slick :D

In javascript you can use
var value = '1.000.000,55';
var splitValue = value.split('.');
for (var i = 0; i < splitValue.length; i++) {
var valPart = splitValue[i];
var newValPart = valPart.replace(',', '.');
splitValue[i] = newValPart;
}
var newValue = splitValue.join(',');
console.log(newValue);

Replace letters in string with the next letter, and capitalize vowels in the changed string

function LetterChanges(str) {
var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
for (var i = 0; i < str.length; i++) {
var index = alphabet.indexOf(str[i])
if (/[a-zA-Z]/.test(str[i])) {
str = str.replace(str[i], alphabet.charAt(index + 1));
}
if (/[aeiou]/.test(str[i])) {
str = str.replace(str[i], alphabet.charAt(index + 26));
}
}
return str;
}
When I call LetterChanges("hello"), it returns 'Ifmmp' which is correct, but when "sent" is passed it returns 'ufOt' instead of 'tfOu'. Why is that?

str.replace() replaces the first occurrence of the match in the string with the replacement. LetterChanges("sent") does the following:
i = 0 : str.replace("s", "t"), now str = "tent"
i = 1 : str.replace("e", "f"), now str = "tfnt"
i = 2 : str.replace("n", "o"), now str = "tfot", then
str.replace("o", "O"), now str = "tfOt"
i = 3 : str.replace("t", "u"), now str = "ufOt"
return str

There are several issues. The main one is that you could inadvertently change the same letter several times.
Let's see what happens to the s in sent. You first change it to t. However, when it comes to changing the final letter, which is also t, you change the first letter again, this time from t to u.
Another, smaller, issue is the handling of the letter z.
Finally, your indexing in the second if is off by one: d becomes D and not E.

You can use String.replace to avoid that:
function LetterChanges(str) {
return str.replace(/[a-zA-Z]/g, function(c){
return String.fromCharCode(c.charCodeAt(0)+1);
}).replace(/[aeiou]/g, function(c){
return c.toUpperCase();
});
}
But there is still a bug: LetterChanges('Zebra') will return '[fcsb'. I assume that is not your intention. You will have to handle the shift.

Try this one:
function LetterChanges(str) {
var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
var result = '';
var temp;
for (var i = 0; i < str.length; i++) {
var index = alphabet.indexOf(str[i])
if (/[a-zA-Z]/.test(str[i])) {
//str = str.replace(str[i], alphabet.charAt(index + 1));
temp= alphabet.charAt(index + 1);
index = index+1;
}
else if(str[i] == ' '){
temp = ' ';
}
if (/[aeiou]/.test(temp)) {
temp = alphabet.charAt(index + 26);
}
result += temp;
}
return result;
}

var str = 'bcd12';
str = str.replace(/[a-z]/gi, function(char) { //call replace method
char = String.fromCharCode(char.charCodeAt(0)+1);//increment ascii code of char variable by 1 .FromCharCode() method will convert Unicode values into character
if (char=='{' || char=='[') char = 'a'; //if char values goes to "[" or"{" on incrementing by one as "[ ascii value is 91 just after Z" and "{ ascii value is 123 just after "z" so assign "a" to char variable..
if (/[aeiuo]/.test(char)) char = char.toUpperCase();//convert vowels to uppercase
return char;
});
console.log(str);

Check this code sample. There is no bug in it. Not pretty straight forward but Works like a charm. Cheers!
function LetterChanges(str) {
var temp = str;
var tempArr = temp.split("");//Split the input to convert it to an Array
tempArr.forEach(changeLetter);/*Not many use this but this is the referred way of using loops in javascript*/
str = tempArr.join("");
// code goes here
return str;
}
function changeLetter(ele,index,arr) {
var lowerLetters ="abcdefghijklmnopqrstuvwxyza";
var upperLetters ="ABCDEFGHIJKLMNOPQRSTUVWXYZA";
var lowLetterArr = lowerLetters.split("");
var upLetterArr = upperLetters.split("");
var i =0;
for(i;i<lowLetterArr.length;i++){
if(arr[index] === lowLetterArr[i]){
arr[index] = lowLetterArr[i+1];
arr[index]=arr[index].replace(/[aeiou]/g,arr[index].toUpperCase());
return false;
}
if(arr[index] === upLetterArr[i]){
arr[index] = upLetterArr[i+1];
arr[index]=arr[index].replace(/[aeiou]/g,arr[index].toUpperCase());
return false;
}
}
}
// keep this function call here
// to see how to enter arguments in JavaScript scroll down
LetterChanges(readline());

Split method and then concatenate

What I need to do is make this function to where it splits each part of the string entered, and then puts pig latin on each word, meaning it adds ay at the end of each word. Here's what I have so far:
function pigLatin(whatWeTitle) {
var alertThis = " ";
var splitArray = whatWeTitle.split(" ");
for ( i = 0; i < splitArray.length; i++) {
alertThis = makeSentenceCase(splitArray[i]) + " ";
var newWord3 = splitArray.substring(1, whatWeTitle.length) + newWord + 'ay';
alert(newWord3);
}
}
Right now, it just takes the first letter of the string and adds it to the end. It doesn't change each word to pig latin, just the whole phrase. I was wondering of anyone could help me with this. THanks.

You need to use [i] to get items of your array :
var word = splitArray[i];
var newWord3 = word.substring(1,word.length) + word[0] + 'ay';
The best, if you want to end up with the whole new sentence, is to change each word an join them at the end :
var splitArray = whatWeTitle.split(" ");
for ( i = 0; i < splitArray.length; i++) {
var word = splitArray[i];
splitArray[i] = word.substring(1,word.length) + word[0] + 'ay';
}
var newSentence = splitArray.join(' ');
alert(newSentence);
If you test a little, you'll see this algorithm doesn't like the dots or comma in your sentence. If you want something stronger, you'd need a regular expression, for example like this :
var newSentence = whatWeTitle.replace(/[^\. ,]+/g, function(word){
return word.slice(1) + word[0] + 'ay';
});
alert(newSentence);
This works by replacing in place the words in the text, using a function to transform each word.

Something like this ?
function pigLatin(whatWeTitle) {
var alertThis = " ";
var splitArray = whatWeTitle.split(" ");
var finalString = "";
for ( i = 0; i < splitArray.length; i++) {
finalString += splitArray[i]+ "ay ";
}
alert(finalString);
}
pigLatin("this is a test");

You probably want to split off the first consonant values and then append them along with 'ay'.
I would use a regex to accomplish this. Here is a JSFiddle showing an example.
First part is split the word
var words = text.split(" ");
Next part is to piglatinify™ each word
words = words.map(function(word){ return pigLatinifyWord(word);});
This is the piglatinify™ function
function pigLatinifyWord(word){
var result;
var specialMatches = word.match(/(\W|\D)+$/);
var specialChars;
if(specialMatches && specialMatches.length >= 0){
var specialIndex = word.indexOf(specialMatches[0]);
specialChars = word.slice(specialIndex);
word = word.substr(0, specialIndex);
}
var i = word.search(/^[^aeiou]/);
if(i >= 0){
result = word.slice(i+1) + word.slice(0, i+1) + "ay";
}
else{
result = word + "ay";
}
if(specialChars){
result += specialChars;
}
return result;
}
Update
JSFiddle example now includes handling for non-word non-digit characters