I am using RegExp on a pattern after reading it from a json file.
json file :
patternToSearch : {
"test" : "/^test/g"
}
In js file I am using this pattern to match with a string
var patternToMatch = "testing";
var pattern = new RegExp(file.patternToSearch[test]);
console.log(pattern.test(patternToMatch);
I get the output as false as instead of /^test/g the pattern is coming out as /\/^test\/g/.
Not able to remove the extra slahes. Could somebody help me out in this?
In your code test is not defined in your case.
var pattern = new RegExp(file.patternToSearch[test]);
^ ^
You have to replace test with a "test".
So this like of code should looks like
var pattern = new RegExp(file.patternToSearch["test"]);
It works too:
var pattern = new RegExp(file.patternToSearch.test);
try this:
var pattern = new RegExp(file.patternToSearch[test].replace(/^\/|\/$/g,''));
because:
console.log(`/\/^test\/g/`.replace(/^\/|\/$/g, ''))Single\doesn't matter while / matters.
And I don't know why you didn't get error using patternToSearch[test].It should be patternToSearch.test unless you have defined variable test.
So i would suggest you try this:
var pattern = new RegExp(file.patternToSearch.test.replace(/^\/|\/$/g,''));
You have seen from other answers that accessing a key without treating it as a string is wrong. Besides, you should split your original regex into two parts: patterns and flags then use them in a RegExp constructor:
var patternToSearch = {"test":"/^test/g"};
var source = patternToSearch.test.match(/\/(.*)\/(.*)/);
// source[1] contains patterns, source[2] contains flags
var pattern = new RegExp(source[1], source[2]);
// Logging our tests
console.log(pattern.test("testing"));
console.log(pattern.test("not-testing"));But before doing this, you have to make sure that tokens and escaped characters are double escaped.
['test']I guess test here should be a string instead of a variable.