C# RegEx string extraction

Question

I have a string:

\"ImageDimension=655x0;ThumbnailDimension=0x0\".

I have to extract first number (\"655\" string) coming in be

Answer 1

var m = Regex.Match(str,@"(\d+).(\d+).*?(\d+).(\d+)");
m.Groups[1].Value; // 655 ....

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(\d+) 

Get the first set of one or more digits. and store it as the first captured group after the entire match

.

Match any character

(\d+)

Get the next set of one or more digits. and store it as the second captured group after the entire match

.*? 

match and number of any characters in a non greedy fashion.

(\d+)

Get the next set of one or more digits. and store it as the third captured group after the entire match

(\d+)

Get the next set of one or more digits. and store it as the fourth captured group after the entire match