s*********y
发帖数: 34 | 1 Q32:
Item 32 of 70 Mark item for review
Consider the following data step:
data WORK.NEW;
set WORK.OLD;
Count+1;
run;
why Icount is assigned a value 0 at compile time, NOT assigned a value of
missing when the data step begins execution. | T****n
发帖数: 2195 | 2 sum statement 的特殊规定。一般的变量定义需要初始化的。直接写变量计算会出错。
sum statement 特殊，默认变量初始值是0，然后每一循环累加到变量中去算总和。
【在 s*********y 的大作中提到】
: Q32:
: Item 32 of 70 Mark item for review
: Consider the following data step:
: data WORK.NEW;
: set WORK.OLD;
: Count+1;
: run;
: why Icount is assigned a value 0 at compile time, NOT assigned a value of
: missing when the data step begins execution.
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