Remove all dots except the first one from a string

Question

Given a string

\'1.2.3.4.5\'

I would like to get this output

\'1.2345\'

(In case there are no dots in the

Answer 1

You could also do something like this, i also don't know if this is "simpler", but it uses just indexOf, replace and substr.

var str = "7.8.9.2.3";
var strBak = str;

var firstDot = str.indexOf(".");
str = str.replace(/\./g,"");
str = str.substr(0,firstDot)+"."+str.substr(1,str.length-1);

document.write(str);

Shai.

Answer 2

var input = '14.1.2';
reversed = input.split("").reverse().join("");
reversed = reversed.replace(\.(?=.*\.), '' );
input = reversed.split("").reverse().join("");

Answer 3

Here is another approach:

function process(input) {
    var n = 0;
    return input.replace(/\./g, function() { return n++ > 0 ? '' : '.'; });
}

But one could say that this is based on side effects and therefore not really elegant.

Answer 4

There is a pretty short solution (assuming input is your string):

var output = input.split('.');
output = output.shift() + '.' + output.join('');

---

If input is "1.2.3.4", then output will be equal to "1.234".

See this jsfiddle for a proof. Of course you can enclose it in a function, if you find it necessary.

EDIT:

Taking into account your additional requirement (to not modify the output if there is no dot found), the solution could look like this:

var output = input.split('.');
output = output.shift() + (output.length ? '.' + output.join('') : '');

which will leave eg. "1234" (no dot found) unchanged. See this jsfiddle for updated code.

Answer 5

Trying to keep this as short and readable as possible, you can do the following:

JavaScript

var match = string.match(/^[^.]*\.|[^.]+/g);
string = match ? match.join('') : string;

Requires a second line of code, because if match() returns null, we'll get an exception trying to call join() on null. (Improvements welcome.)

Objective-J / Cappuccino (superset of JavaScript)

string = [string.match(/^[^.]*\.|[^.]+/g) componentsJoinedByString:''] || string;

Can do it in a single line, because its selectors (such as componentsJoinedByString:) simply return null when sent to a null value, rather than throwing an exception.

As for the regular expression, I'm matching all substrings consisting of either (a) the start of the string + any potential number of non-dot characters + a dot, or (b) any existing number of non-dot characters. When we join all matches back together, we have essentially removed any dot except the first.

Answer 6

var i = s.indexOf(".");
var result = s.substr(0, i+1) + s.substr(i+1).replace(/\./g, "");

Somewhat tricky. Works using the fact that indexOf returns -1 if the item is not found.