替换通用字符串的出现

Question

I never was good enough with regex, and I assume this is the job for it.

I have a link like www.somelink/phoyto.jpg/?sz=50

I need to replace 50 with my value, let's say 100. Trouble is, that I cannot be sure, that this will be always sz=50 and not sz=150 or sz=10 or any other value.

What I need is to find an occurence of string contains of 'sz' + number and replace it with 'sz=100' .

Sure, I can do that 'manually" in some for loop, but that wouldn't be nor smar nor efiicient.

Answer 1

str = "www.somelink/phoyto.jpg/?sz=50";
str.replaceall("sz=\\d+", "sz=100");

\\d is the java pattern for digit. + stands for one or more digits. replaceall replaces all occurrences of sz=<number> .

Here is a handy online regex tester for java: http://www.regexplanet.com/advanced/java/index.html

Answer 2

This should work:

String link = "www.somelink/phoyto.jpg/?sz=50";
link = link.replaceFirst("sz=\\d+", "sz=100");
System.out.println(link);

Answer 3

It's pretty simple, and this pattern should work:

(sz=\d+)

Code:

String result = searchText.replaceAll("(sz=\\d+)", "sz100");

Example:

http://regex101.com/r/mB3xT9