c - Why printf("test"); does not give any error? -

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if int x=printf("test"); executes safely, without error in because printf returns int value (the length of data has printed.) if not storing integer value:

printf("text");

why don't error this?

many functions in c return something. whether programmer decides value them - , ignoring return code leads bugs... in case of printf(), return value seldom useful. provided allow following code:

int width;  width = printf("%d", value); // find out how wide while (width++<15) printf(" "); width = printf("%s", name); while (width++<30) printf(" ");

i'm not saying that's code (there other ways too!), describes why function return value isn't used often.

if programmer decide ignore return value, there isn't compiler error - value merely forgotten. it's bit buying something, getting receipt, , dropping on floor - ignore returned value.

the latest compilers can instructed flag code returned values ignored. these compilers can taught functions' returns significant , aren't. printf() in second category.


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