string = c("apple", "apples", "applez") grep("apple", string)
这将为我提供所有三个元素的索引string.但我希望在单词"apple"上完全匹配(即我只想grep()返回索引1).
string
grep()
regex grep r word-boundary gsub
grep ×1
gsub ×1
r ×1
regex ×1
word-boundary ×1