Sum by column with same row value on other variable , not using proc

[AlohaHi]

Hi

it may or may not sound easy and not even sure u can understand what I am trying to do.

My question is that "without using proc"

and if my data table is shown like this

Var1 Var2

A        3

A        20

B        1

C        4

C        5

is it possible to sum column values with same var1 value,

which means 3+20 because they got Same Var1 value A

and 4+5 for C,

that makes new variable Var3 on the table.

if I just used

Var3 = Var3+Var2;

retain Var3 0;

it would just give the whole sum of numbers no matter what value they've got on Var1.

[PeterClemmensen]

@AlohaHi Hi and welcome to the SAS Community 🙂

You need to control your By Groups and do something like this

data have;
input Var1 $ Var2;
datalines;
A 3
A 20
B 1
C 4
C 5
;

data want;
    set have;
    by Var1;
    if first.Var1 then Var3=0;
    Var3+Var2;
run;

[AlohaHi]

is it not possible to do within one data step? 

[PeterClemmensen · Accepted solution]

It is 1 data step? The first one simply creates the data to work with.

[ed_sas_member]

Hi @AlohaHi 

If you don't want to use a PROC, you can use the following code, assuming the dataset is sorted by Var1

data have;
	input Var1 $ Var2;
	cards;
A 3
A 20
B 1
C 4
C 5
;
run; 

data want;
	set have;
	by Var1;
	
	if first.var1 then Var3 = 0;
	Var3 + Var2;
	
	if last.var1 then output;
	
	drop var2;
run;