Let's say I have these two strings: "5/15/1983" and "1983.05.15". Assume that all characters in the string will be numeric, except a "separator" character that can appear anywhere in the string. There will be only one separator character; all instances of any given non-numeric character in the string will be identical.
How can I use regex to extract this character? Is there a more efficient way than the one below?
"05-15-1983".replace(/\d/g, "")[0];
Thanks!
"05-15-1983".match(/\D/)
Technically, this returns an array containing one string, but it will implicitly convert to the string most places you need this.
[0]. Further, "05-15-1983".match(/\D/)[0] and "05-15-1983".match(/\D/)[0][0] are exactly equivalent. There is no char type, so indexing returns a string. In fact, you can add as many [0]s as you want. I do think this answer is better, since your example forces the evaluator to look at every letter, and do (trivial) concatenation. My answer will stop after finding the first non-digit.Though i could not exactly get what you trying to do i tried to extract the numbers only in one string and the seperator in next string.
I used the above:
<script>
var myStr1 = "1981-01-05";
var myStr2 = "1981-01-05";
var RegEx1 = /[0-9]/g;
var RegEx2 = /[^0-9]/g;
var RegEx3 = /[^0-9]/;
document.write( 'First : ' + myStr1.match( RegEx1 ) + '<br />' );
document.write( 'tooo : ' + myStr2.replace( RegEx2, "" ) + '<br />' );
document.write( 'Second : ' + myStr1.match( RegEx2 ) + '<br />' );
document.write( 'Third : ' + myStr1.match( RegEx3 ) + '<br />' );
</script>
Output:
First : 1,9,8,1,0,1,0,5
tooo : 19810105
Second : -,-
Third : -
I hope you get your answer
Clearly tired or not paying attention on my previous answer. Sorry about that. What I should have written was:
var regexp = new RegExp("([^0-9])","g");
var separator = regexp.exec("1985-10-20")[1];
Of course, Matthew Flaschen's works just as well. I just wanted to correct mine.
exec is a function on RegExp, not String, and the returned array has length 1, so 1 is not a valid index.
"g" flag for the same reason he stated (in the comments).