Is there a JavaScript strcmp()?
JavascriptStringStrcmpJavascript Problem Overview
Can anyone verify this for me? JavaScript does not have a version of strcmp(), so you have to write out something like:
( str1 < str2 ) ?
-1 :
( str1 > str2 ? 1 : 0 );
Javascript Solutions
Solution 1 - Javascript
What about
str1.localeCompare(str2)
Solution 2 - Javascript
Javascript doesn't have it, as you point out.
A quick search came up with:
function strcmp ( str1, str2 ) {
// http://kevin.vanzonneveld.net
// + original by: Waldo Malqui Silva
// + input by: Steve Hilder
// + improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// + revised by: gorthaur
// * example 1: strcmp( 'waldo', 'owald' );
// * returns 1: 1
// * example 2: strcmp( 'owald', 'waldo' );
// * returns 2: -1
return ( ( str1 == str2 ) ? 0 : ( ( str1 > str2 ) ? 1 : -1 ) );
}
from http://kevin.vanzonneveld.net/techblog/article/javascript_equivalent_for_phps_strcmp/
Of course, you could just add localeCompare if needed:
if (typeof(String.prototype.localeCompare) === 'undefined') {
String.prototype.localeCompare = function(str, locale, options) {
return ((this == str) ? 0 : ((this > str) ? 1 : -1));
};
}
And use str1.localeCompare(str2)
everywhere, without having to worry wether the local browser has shipped with it. The only problem is that you would have to add support for locales
and options
if you care about that.
Solution 3 - Javascript
localeCompare()
is slow, so if you don't care about the "correct" ordering of non-English-character strings, try your original method or the cleaner-looking:
str1 < str2 ? -1 : +(str1 > str2)
This is an order of magnitude faster than localeCompare()
on my machine.
The +
ensures that the answer is always numeric rather than boolean.
Solution 4 - Javascript
var strcmp = new Intl.Collator(undefined, {numeric:true, sensitivity:'base'}).compare;
Usage: strcmp(string1, string2)
Result: 1
means string1 is bigger, 0
means equal, -1
means string2 is bigger.
This has higher performance than String.prototype.localeCompare
Also, numeric:true
makes it do logical number comparison
Solution 5 - Javascript
from this How to Check if Two Strings are Equal in JavaScript article:
-
Generally, if your strings contain only ASCII characters, you use the
===
operator to check if they are equal. -
But when your strings contain characters that include combining characters(eg.
e + ◌́ = é
), you normalize them first before comparing for equality as follows-s1.normalize() === s2.normalize()
Solution 6 - Javascript
How about:
String.prototype.strcmp = function(s) {
if (this < s) return -1;
if (this > s) return 1;
return 0;
}
Then, to compare s1 with 2:
s1.strcmp(s2)