我正在使用 stringr 包学习正则表达式。我自己的一个练习是查找包含某个子字符串的字符串的数量。正确的做法是
length(str_subset(words,'ing$'))
一路走来我错误的尝试
length(str_view(words,'ing$'))
第二个例子给出了错误的结果 8。但是在尝试不同的事情时，第二个命令always给出的结果是 8，无论我正在搜索什么以及我试图匹配哪个正则表达式。
为什么我在第二种情况下总是得到答案8？它找到的长度是多少？
我尝试了几组不同的字符串，但总是得到相同的答案。我想出了如何正确地做到这一点，但令我惊讶的是，我尝试的错误方法总是给出相同的数字 8。
str_viewnames(str_view(...))[1] "x" "width" "height" "sizingPolicy"
[5] "dependencies" "elementId" "preRenderHook" "jsHooks"
可以在
str_view(...)$x$htmlstr_view(letters[1:3], 'a')$x$html
<ul>
<li><span class='match'>a</span></li>
<li>b</li>
<li>c</li>
</ul>
希望有帮助:)
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今天在广告窗口中出现给我。 其他人也有同样的问题...