将变量插入正则表达式（JavaScript）不起作用

Question

This is my code:

var newLT = 'locTable'+(l+locations);
var findLT = 'locTable'+l;
var regex = new RegExp("/\b" + findLT + "\b/g");
locOrig = locOrig.replace(regex, newLT);

I'm trying to replace all instances of 'locTable(#number here)' with the newLT variable.

So for example if this was in a string <input id="locTable3_0"> ideally I could replace just the 'locTable3' part which is stored in findLT with the value in newLT.

Any tips on what I'm doing wrong?

EDIT: For clarity:

Say I have the string <input id="locTable3_0"> .

variable newLT is equal to locTable4

variable findLT is equal to locTable3

I want to have a regex which finds locTable3 and replaces it with locTable4 so that my resulting string is <input id="locTable4_0">

Answer 1

Updated: I think I god it now

var regex = /locTable\d/;
var newString = 'something_else_3'
var string = "locTable3_0";
var result = string.replace(regex1, newString);

this will result in something_else_3_0

Answer 2

• /.../xyz is short notation, that won't work here

new RegExp("/\\b" + findLT + "\\b/g"); => new RegExp("\\b" + findLT + "\\b", "g");

• You are passing string to RegExp constructor, so you have to escape special chars twice:

new RegExp("\\b" + findLT + "\\b", "g"); => new RegExp("\\\\b" + findLT + "\\\\b", "g");