Question

string str="this image has the width of 200px and height of 100px.";
int width, height;

How can I code to get

width= 200;
height=100;

If width is more than 150, i will reduce the width to 150 and i will calculate the height

if(width>150)
{
 height=(height*150)/200;
 width=150;
}

And the result string would be..

str="this image has the width of 150px and height of 75px.";

I know substring() indexOf() split()

I know i can split the string with “width” but I dunno how to find the number of that splitted string.

Answer 1

There’s a few parts to this. First I would suggest a regular expression to match part of the string and explicitly capture the numeric parts of it.

eg, a possible regular expression could be:

width\sof\s(?<width>\d+)px\sand\sheight\sof\s(?<height>\d+)px

Which matches “width of XXXpx and height of YYYpx” where XXX is captured as a named group width and YYY is captured as a named group height.

Here’s the code so far:

string str="this image has the width of 200px and height of 100px.";
var regex = new Regex(@"width\sof\s(?<width>\d+)px\sand\sheight\sof\s(?<height>\d+)px");
var match = regex.Match(str);

Now that match has 2 groups named width and height as previously described. Then you use can use int.Parse on the capture groups to get the values as numbers:

var width = int.Parse(match.Groups["width"].Value);
var height = int.Parse(match.Groups["height"].Value);

The last part, changing the number and re-formulating the string you seem to have a good grasp of, so I havent included that.

Here’s a live example to demonstrate all of the above: http://rextester.com/rundotnet?code=CLPS3633