topic Re: Efficiently Amend/Edit Character String Values in SAS Programming

Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 05:55:11 GMT

Please see following dataset snippet:

i_X
_20205_2
_21102a_5
_20103_5
_20902_2
_21405_3
_22805_3
_21506ab_3
_22304_5
_23003_4
_20903_4

The following is what I want:

i_X             iX
_20205_2        _20205
_21102a_5       _21102a
_20103_5        _20103
_20902_2        _20902
_21405_3        _21405
_22805_3        _22805
_21506ab_3      _21506ab
_22304_5        _22304
_23003_4        _23003
_20903_4        _20903

Here is partial code for bringing this about:

data want;
set have;
iX = i_X;
run;

Next iX values have to be edited, or amended. The final two characters of each value must be deleted. Example: _2 in the first case.

Help with this greatly appreciated.

Nicholas Kormanik

Re: Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 02:18:12 GMT

Possible answer:

catx("_%", iX;

Maybe something like this?

Re: Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 02:25:39 GMT

Another possibility:

iX = scan(iX,-2);

I haven't tried the above two approaches.

Thinking I'd rather wait for the experts' advice.

Re: Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 02:37:30 GMT

Whoa! And finally there's Ksharp's (Xia Keshan) answer to a similar question:

Perl Regular Expression is the most simple powerful flexible method for such question:

string=prxchange('s/\++$//',-1,strip(ur_string));

Good grief. Help Mr. Wizzard.....

Re: Efficiently Amend/Edit Character String Values

Reeza — Sun, 04 Sep 2016 03:46:10 GMT

Your strings are fixed length. Use substr.

Re: Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 05:52:33 GMT

Reeza, unfortunately some of the strings are longer than others. I'll change my example to show that.

If not fixed length, what's the best answer?

Re: Efficiently Amend/Edit Character String Values

Shmuel — Sun, 04 Sep 2016 06:16:42 GMT

1) assuming you need truncate exactly last two caharcters:

ix = substr(i_x,1,length(ix)-2);

2) assuming ix is made of 2 substrings separated by underscores and

the 1st character should be an underscore:

ix = '_' || scan(i_x,1,'_');

Re: Efficiently Amend/Edit Character String Values

NKormanik — Sun, 04 Sep 2016 07:36:21 GMT

Wow. So five or six ways of doing it, so far.

And others are likely to follow?

Re: Efficiently Amend/Edit Character String Values

Ksharp — Sun, 04 Sep 2016 07:58:55 GMT



data have;
input i_X $20.;
string=prxchange('s/_\d+$//',-1,strip(i_x));
cards;
_20205_2
_21102a_5
_20103_5
_20902_2
_21405_3
_22805_3
_21506ab_3
_22304_5
_23003_4
_20903_4
;
run;

Re: Efficiently Amend/Edit Character String Values

NKormanik — Mon, 05 Sep 2016 09:26:04 GMT

Excellent contributions. Surely useful for future reference, and searches for answers by others.

HOWEVER, in this present case, it appears the winner is as follows:

data want;
set have;
iX = scan(i_X,-2,"_");
run;

Easier to understand.