R的替换sub和gsub

sub(pattern, replacement, x, ignore.case = FALSE, perl = FALSE,
fixed = FALSE, useBytes = FALSE)

gsub(pattern, replacement, x, ignore.case = FALSE, perl = FALSE,
fixed = FALSE, useBytes = FALSE)

> text<-c("Hello Adam!\nHello Ava!")

> sub(pattern="Adam|Ava",replacement="world", text) #只做一次替换（不管有几次匹配）
[1] "Hello world!\nHello Ava!"

> gsub(pattern="Adam|Ava",replacement="world", text) #满足条件的匹配都做替换
[1] "Hello world!\nHello world!"

> text #原字符串并没有改变
[1] "Hello Adam!\nHello Ava!"