Hi, Community    I am trying to create a new variable combining two variables. My data looks like this (if pre_a has a value, post_a doesn't. If post_a has a value, pre_a doesn't..):    pre_a post_a pre_b post_b  2       .            3         .  .        .            .          2 .        3           3         . .        3           .           .    I would like to create a new variable 'Apple' combining pre_a and post_a, and 'Ball' combining pre_b and post_b. The dataset I would like to get looks like this:   pre_a post_a apple     pre_b post_b ball  2       .             2             3         .         3 .        .              .             .          2        2  .        3            3            3.          .        3 .        3            3             .          .         .    I tried to use the following code:   apple=pre_a; if apple ne ' ' then output; apple=post_a; if apple ne ' ' then output; ball=pre_b; if ball  ne ' ' then output; ball=post_b; if ball  ne ' ' then output; keep apple ball; run;    If using the code, I got the apple variable, correctly, but not a ball variable. Could you give some advice to do this? Or, is there different way to create a new variable combining two variables?    Your answers would be very helpful! Thanks!           ... View more