myString.replace( VARIABLE, "") ...... but globally

Question

How can I use a variable to remove all instances of a substring from a string? (to remove, I'm thinking the best way is to replace, with nothing, globally... right?)

if I have these 2 strings,

myString = "This sentence is an example sentence."
oldWord = " sentence"

then something like this

myString.replace(oldWord, "");

only replaces the first instance of the variable in the string.

but if I add the global g like this myString.replace(/oldWord/g, ""); it doesn't work, because it thinks oldWord, in this case, is the substring, not a variable. How can I do this with the variable?

Solution 1

Well, you can use this:

var reg = new RegExp(oldWord, "g");
myString.replace(reg, "");

or simply:

myString.replace(new RegExp(oldWord, "g"), "");

Solution 2

You have to use the constructor rather than the literal syntax when passing variables. Stick with the literal syntax for literal strings to avoid confusing escape syntax.

var oldWordRegEx = new RegExp(oldWord,'g');

myString.replace(oldWordRegEx,"");

Solution 3

No need to use a regular expression here: split the string around matches of the substring you want to remove, then join the remaining parts together:

myString.split(oldWord).join('')

In the OP's example:

var myString = "This sentence is an example sentence.";
var oldWord = " sentence";
console.log(myString.split(oldWord).join(''));

Comments

[Derek 朕會功夫]

Woot! Is that copying from me?

[Erik Reppen]

I just type slower and offer more advice.

[Erik Reppen]

Sigh... always a bridesmaid never an answer.

[Camilo Martin]

Boom: var oldWord = '\\';

[Derek 朕會功夫]

This does not answer the question.

[bra_racing]

The question is about replacing the content of a variable