I trying to get user input match it against a string variable, when I passed a literal string to new RegExp(/\bjavascript/), it works, but I tried new RegExp('\b' + this.input) or new RegExp('/\b' + this.input + '/'); it fails.
Here is the code
var lang = 'javascript'
let patern = new RegExp('/\b' + this.input + '/');
console.log(patern.test('lang'));
where 'input' is declare within my class
Remove the slash from the beginning and end and escape backslashes:
this.input = "St";
let pattern = new RegExp('\\b' + this.input, 'i');
console.log(
"Stack Overflow".match(pattern)
)
new RegExp('\\b' + this.input, 'i'); will give you a case-insensitive regexWhen input comes from a user, it's a good idea to escape the string using the following:
RegExp.escape = function (s)
{
return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
};
You call it like this:
let patern = new RegExp('\\b' + RegExp.escape(this.input));
That way it Works even when the input has special characters in it, like '\' or parenthesis-
