while true vs. for i= 1:Inf

So I was recently posed with the question, what is the difference between a while true loop and a for i = 1:Inf loop. I have done quite a bit of research, but I cannot seem to come up with an answer. Do you know?

回答(3 个)

per isakson
per isakson 2012-12-13

2 个投票

The for-loop provide the loop-variable, ii. Why, is that interesting?
James Tursa
James Tursa 2012-12-13
编辑:James Tursa 2012-12-13

1 个投票

In addition to what Per Isakson has written, I would add that the loop variable, after a certain point, will lose precision and become ill-defined. I think MATLAB will try to gracefully provide a value for ii, but after a point the successive ii's will be equal to each other until the background rounding scheme clocks it over into the next representable value. (As I recall, there was a previous similar thread some time ago that explored this topic)

2 个评论

Warning: Warning: FOR loop index is too large. Truncating to 281474976710655
There is also a MISRA-C rule regarding a while true vs a for loop in C, but I do not know if that extends to Matlab

请先登录,再进行评论。

k=0;
while rand<0.8
k=k+1;
end
The while loop will run until a condition rand < 0.8 is false, we don't know when it occurs, because rand is a random number. In this case we can't use a for loop

2 个评论

Why not? Even if slightly longer code...
for k=1:Inf,
if rand>=0.8,
break,
end;
end;
Because it might take more than 281474976710655 iterations which is the limit for 1:inf loops.

请先登录,再进行评论。

类别

帮助中心File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by