[R] Placeholders for String Operations

Rui Barradas ruipbarradas at sapo.pt
Wed Sep 4 18:36:59 CEST 2013


Hello,

I'm not sure I understand, but if you want a ?regexp to only match 
numbers before a %, try the following.


gsub("[0-9]+%", "[percentagevalue]", text1)
gsub("[0-9]+%", "[percentagevalue]", text2)


[0-9] matches any character in the range from 0 to 9, and the + means to 
repeat that character any number of times. See the help page for ?regexp.

Hope this helps,

Rui Barradas

Em 04-09-2013 16:17, Simon Pickert escreveu:
> Hi all,
>
> what are the placeholders for string operations/modifications? Is there a placeholder for numbers, which would allow me to easily replace all numbers in a string? Something like
>
> text1 <- c("this is a number 23%")
> text2 <- c("this is not a number bla%")
>
> newtext1 <- gsub(#%, [percentagevalue], text)
> newtext2 <- gsub(#%, [percentagevalue], text)
>
>
> newtext1  should be "this is a number [percentagevalue]"
> newtext2  should be "this is not a number 23%"
>
>
> I figured there is * ? . but I can't find a source that explains their use and lists other placeholders..
>
>
> Appreciate your help!
> Thanks
> Simon
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