(Multiple) Replace string with array

Question

I have a large string which need be replaced a few times. Such as

var str="Username:[UN] Location:[LC] Age:[AG] ... "

str=str.replace("[UN]","Ali")
str=str.replace("[LC]","Turkey")
str=str.replace("[AG]","29")
...
//lots of replace
...

Is there a way to put those FIND and REPLACE parameters to an array, and replace all of them at once? Such as:

reps = [["UN","Ali"], ["LC","Turkey"], ["AG","29"], ...]
$(str).replace(reps)

@KrzysztofSafjanowski it should be the other way around since this one is older than your duplicate proposal — Nicolas Filotto, Nov 03 '16 at 11:38

score 26 · Accepted Answer · edited May 23 '17 at 12:31

26

No jQuery is required.

var reps = {
  UN: "Ali",
  LC: "Turkey",
  AG: "29",
  ...
};

return str.replace(/\[(\w+)\]/g, function(s, key) {
   return reps[key] || s;
});

The regex /\[(\w+)\]/g finds all substrings of the form [XYZ].
Whenever such a pattern is found, the function in the 2nd parameter of .replace will be called to get the replacement.
It will search the associative array and try to return that replacement if the key exists (reps[key]).
Otherwise, the original substring (s) will be returned, i.e. nothing is replaced. (See In Javascript, what does it mean when there is a logical operator in a variable declaration? for how || makes this work.)

edited May 23 '17 at 12:31

Community

1
1

answered Jan 31 '11 at 06:45

kennytm

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2

+1, although: This assumes the replacement will never be an empty string. @user: If sometimes the replacements are empty strings, change the body of the function to `var rep = reps[key]; return typeof rep === "undefined" ? s : rep;` – T.J. Crowder Jan 31 '11 at 06:55
Just tried it in Chrome's console, it doesn't work. `var reps = { UN: "Ali", LC: "Turkey", AG: "29" };`, then `var str = "hello UN, I'm in LC, AG"`, and finally `str.replace(/\[(\w+)\]/g, function(s, key) { return reps[key] || s; });` returns the inital string, without any replacement. – DevonDahon Apr 02 '19 at 11:24
@maxagaz Please check OP's question, the `str` is `var str = "Username:[UN] Location:[LC] Age:[AG]"`. There are brackets around the UN, LC and AG. – kennytm Apr 02 '19 at 18:24

score 4 · Answer 2 · answered Jan 31 '11 at 06:46

4

You can do:

var array = {"UN":"ALI", "LC":"Turkey", "AG":"29"};

for (var val in array) {
  str = str.split(val).join(array[val]);
}

answered Jan 31 '11 at 06:46

Sarfraz

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(Multiple) Replace string with array

2 Answers2