var str = "Visit tEsT!";
var ara = "test";
let n = str.search(/\b + ara + \b/i); // Sadly code doesn't run
document.getElementById("demo").innerHTML = n;
I want find ara variable in str variable with regex search().
-
1Pleas explain clearly what is the result you want..Abhilash Chandran– Abhilash Chandran2020-01-29 15:41:02 +00:00Commented Jan 29, 2020 at 15:41
-
İ want find "ara" variable in "str" variable with regex search().Soru İşareti– Soru İşareti2020-01-29 15:43:14 +00:00Commented Jan 29, 2020 at 15:43
Add a comment
|
5 Answers
You need to define a new regex from a string in order to use variables.You can do this with new RegExp(). You will also need the i option for case insensitive mode.
var str = "Visit tEsT!";
var ara = "test";
var regex = new RegExp(`\\b${ara}\\b`, 'i'); // Evaluates to "/\btest\b/i"
let n = str.search(regex);
document.getElementById("demo").innerHTML = n;
2 Comments
Soru İşareti
Thank you for fastly help :)
Soru İşareti
ara.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g, '') @FZs
You have to put variables like this in Regex:
var str = "Visit tEsT!";
var ara = "test";
let n = str.search(new RegExp(`\\b${ara}`,"i"));
console.log(n);More secure way is to remove special chars:
str.replace(/[^A-Za-z0-9\s\n]/g,"")
var str = "Visit tEsT!";
var searchstr = "test &#";
let n = str.search(new RegExp(`\\b${searchstr.replace(/[^A-Za-z\\s\\n]/g,"")}`,"i"));
console.log(n);
1 Comment
Soru İşareti
Thank you for fastly help :)
In your regular expression, you cannot use the + operator as a string concatenator. Instead, you could use for example template strings and create the regular expression with new RegExp:
var str = "Visit tEsT!";
var ara = "test";
var regex = new RegExp(`\\b${ara}\\b`, 'gi'); // use 'gi' flags to search globally and ignore case
let n = str.search(regex);
console.log(n);
4 Comments
ButchMonkey
You can use
+ for concatenation. You also need to escape \bSoru İşareti
Thank you for fastly help :)
SparkFountain
@ButchMonkey Thanks for your advice. I thought I had to double escape but the PlayCode.io syntax highlighting confused me...
ButchMonkey
NP. I should clarify that you can use
+ for concatenation in new RegExp as it creates a regex from string. But you are correct that you cannot use + in /.*/g syntax as it will be evaluatedIf you want the matched string, use match() instead. The return value n will be an array and its first value (n[0]) will be the matched string.
var str = "Visit tEsT!";
var ara = "test";
var regexp = new RegExp("\\b"+ara+"\\b", 'gi')
n = str.match(regexp);
document.getElementById("demo").innerHTML = n[0];
4 Comments
Soru İşareti
Thank you for your help too i maked search engine for my blog but if i use indexOf() visitor search value "a" then it show all articles ... İ just want to filter with regex to make results better...
PHP Guru
Why do you want to show the index of the matched expression? That's what String.prototype.search() does.
Soru İşareti
let str = 'B ad ga'; let result = str.search('a'); document.write(result); but when i run this code, answer is: "2" so search() like indexOf()PHP Guru
Yes. It's exactly like indexOf except it expects a regular expression.
Using search and match multiple ways.
var str = "Visit tEsT!";
var ara = "test";
let n = str.search(new RegExp('\\b' + ara + '\\b', 'i'))
let n2 = str.match(new RegExp('\\b' + ara + '\\b', 'i')).index;
//document.getElementById("demo").innerHTML = n;
console.log(n, n2)
answered Jan 29, 2020 at 16:29
Siva Kondapi Venkata
11.1k2 gold badges20 silver badges32 bronze badges