JavaScript: case

I'm trying to get a case-insensitive search with two strings in JavaScript working.

Normally it would be like this:

var string="Stackoverflow is the BEST";
var result= string.search(/best/i);
alert(result);

The /i flag would be for case-insensitive.

But I need to search for a second string; without the flag it works perfect:

var string="Stackoverflow is the BEST";
var searchstring="best";
var result= string.search(searchstring);
alert(result);

If I add the /i flag to the above example it would search for searchstring and not for what is in the variable "searchstring" (next example not working):

var string="Stackoverflow is the BEST";
var searchstring="best";
var result= string.search(/searchstring/i);
alert(result);

How can I achieve this?

---

Yeah, use .match , rather than .search . The result from the .match call will return the actual string that was matched itself, but it can still be used as a boolean value.

var string = "Stackoverflow is the BEST";
var result = string.match(/best/i);
// result == 'BEST';

if (result){
    alert('Matched');
}

Using a regular expression like that is probably the tidiest and most obvious way to do that in JavaScript, but bear in mind it is a regular expression, and thus can contain regex metacharacters. If you want to take the string from elsewhere (eg, user input), or if you want to avoid having to escape a lot of metacharacters, then you're probably best using indexOf like this:

matchString = 'best';
// If the match string is coming from user input you could do
// matchString = userInput.toLowerCase() here.

if (string.toLowerCase().indexOf(matchString) != -1){
    alert('Matched');
}

---

Replace

var result= string.search(/searchstring/i);

with

var result= string.search(new RegExp(searchstring, "i"));

---

If you're just searching for a string rather than a more complicated regular expression, you can use indexOf() - but remember to lowercase both strings first because indexOf() is case sensitive:

var string="Stackoverflow is the BEST"; 
var searchstring="best";

// lowercase both strings
var lcString=string.toLowerCase();
var lcSearchString=searchstring.toLowerCase();

var result = lcString.indexOf(lcSearchString)>=0;
alert(result);

Or in a single line:

var result = string.toLowerCase().indexOf(searchstring.toLowerCase())>=0;

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