Why are multiple assignments in one line considered bad style? [closed]

Answer 1

There is no problem as long as you know they should all be the same value.

e.g.

changing

x = y = z = 10;

to

x = y = z = 15;

is very easy.

If however, they are arbitrarily the same, separate assignments convey this, and are easier to change individually for testing.

x = 10;
y = 10;
z = 10;

to

x = 10;
y = 15;
z = 10;

is better than having to break up the line.

The key is what you are telling the next programmer to look at the code (or yourself in 6 months).

Answer 2

It's not inherently bad style, but you can often make the code clearer by doing just one assignment per line and letting the compiler optimizer sort things out. If you use the multiple-assignment style then sometimes it might not be clear whether x = y = z = 10; was intentional or whether it was a typo for something like x = y = z + 10;. By always limiting yourself to one assignment per statement you make it obvious when typos occur.

Answer 3

Try it out with those definitions:

int x;
bool y;
int z;
x = y = z = 10;

And be surprised about the value of x.