Replace text with JavaScript

Question

I need to replace text using Javascript. It's a little different than the other ones I've seen on S.O. because the text that needs to be added in is an incrementing integer.

For example: Replace the string: "John Mary Ellen Josh Adam" with "John1 Mary2 Ellen3 Josh4 Adam5"

• Felix Kling: So what precisely do you want to do? Append a number to each word, where "word" is defined as consecutive alphabetical characters, separated by white spaces?
• zod: how you know you have to add the integer.. if there is a space can you add it. What is the condition tocheck

Answer 1

Use a callback replacer:

var str = "John Mary Ellen Josh Adam", i=0;
str = str.replace(/ /g,function(m) {i++; return i+" ";});

EDIT: Noticed that won't add a number after "Adam". That can be fixed just by adding:

i++; str += i;

at the end of the code.

EDIT2: Or all-in-one:

str = str.replace(/ |$/g,function(m) {i++; return i+m[0];});

• robmisio: About adding a number after "Adam": you could also adjust the regex to match the end of the string, e.g. str.replace(/ |$/g, ....
• Niet the Dark Absol: That would add an extra space on the end, though, because of what the function returns.
• user739866: I liked this - especially the elegance of it - but felt it better to use the jsfiddle option rather than adding in an extra line of code. Perhaps that's just my inexperience.
• Patrick Oscity: you could also match the words instead of the spaces, see my answer. That way John Mary (two spaces) yields John1 Mary2, not John1 2 Mary3

Answer 2

You can do it this way:

var array = string.split(" "), i, j;
for(i=0,j=array.length,string="";i<j;string+=array[i]+(++i)+" ");

Answer 3

var input = "John Mary Ellen Josh Adam";
var i = 0;
var output = input.replace(/\w+/g, function(m){ return m + ++i });

output is:

"John1 Mary2 Ellen3 Josh4 Adam5"

• gen_Eric: Couldn't RegExp.lastMatch be replaced with the 1st parameter passed to the callback? Which is more efficient?

Answer 4

I quickly hacked this up. Not sure how efficient it is, but it works.

var x = 1, str = "John Mary Ellen Josh Adam",
newStr = str.replace(/\b([^\s]*)\b/g, function(i){
 return i && (i + (x++));
});

Answer 5

I put together this jsfiddle for you.

This is the code:

var originalStr = "John Mary Ellen Josh Adam";
var splitStr = originalStr.split(' ');
var newStr = "";
for (var i = 0; i < splitStr.length; i++)
 newStr += splitStr[i] + (i+1) + ' ';
alert(newStr);

• Felix Kling: Please include the code in your answer as well as some explanation.
• robmisio: This results in a trailing space on the string.
• Patrick Oscity: i agree @robmisio, that shouldn't be happening