function example(){
var quantity = "http://www.example.com/index.php?brandid=b%123&quantity=20";
quantity = quantity.replace(-what regular expression should i user-, "quantity=50");
}
i want to replace only the quantity=20 to quantity=50 in link. but i have tried some of the regular expression such as：
replace(/quantity=[^\d]/g,"quantity=50")；
replace(/quantity=[^0-9]/g,"quantity=50")；
so i would like to have some help from expertise in regular expression to help me =) thanks
replace(/quantity=[\d]+/g,"quantity=50")
+ outside of the brackets or--better still--not use the brackets at all. Everything inside the character class represents one character.
?some_other_quantity=5&quantity=9?
replace(/[?&]quantity=\d+([&]?)/g,"$1quantity=50$2")；
try this ^
([?&])
group together either symbol '?' or '&' (one and only one char) as the group named $1
\d+
find at least one digit and find the longest consecutive string of digits if there is >1 digits
([&]?)
group together either empty string (if at the end) or '&' as the group named $2
'?' means match zero or one time
by grouping a group of match in ()...()....() and then use it in the result as $1,$2,$3... you can do search and replace plus many more complex operations.
Here is one way you could do it. It will only ever work with the query string, not the entire URL.
function example(){
var quantity = 'http://www.example.com/index.php?brandid=b%123&quantity=20',
a = document.createElement('a');
a.href = quantity;
a.search = a.search.replace(/([?&;]quantity=)\d+/, '$150');;
return a.href;
}
? so that should probably be a.search = a.search.replace(/([&^;\?]quantity=)[\d\.]+/, '$150'); Added a decimal too, just in case.
^in the [0-9] part. The caret there says to find anything but what follows. Instead, try this:[0-9]+, as it will match any number one or more times.