I'm learning about regular expressions with the stringr package. An exercise for myself was to find the number of strings containing a certain substring. The right way to do this is
length(str_subset(words,'ing$'))
Along the way I incorrectly tried
length(str_view(words,'ing$'))
That second example gave the incorrect result 8. But in trying different things, that second command always gave the result of 8 regardless of what I was searching and which regex I was trying to match.
Why was I always getting the answer 8 in the second case? What is it finding the length of?
I tried several different sets of strings and always got the same answer. I figured out how to do it correctly, but was surprised the wrong way I tried always gave the same number 8.
str_view isn't a string output, it's an object which has 8 fixed fields that help it draw the diagram e.g. names(str_view(...)) gives you those objects
[1] "x" "width" "height" "sizingPolicy"
[5] "dependencies" "elementId" "preRenderHook" "jsHooks"
Can see in the str_view(...)$x$html value the ones where the string has matched:
str_view(letters[1:3], 'a')$x$html
<ul>
<li><span class='match'>a</span></li>
<li>b</li>
<li>c</li>
</ul>
Hope that helps :)