What is wrong with for loop iteration that is put in a function?
显示 更早的评论
Hi! I'm wondering on this code I made:
a = input('Please insert a: ')
b = input('Please insert b: ')
arr = []
for i = a:b-1
for j = a+1:b
if and(composite(i), composite(j), composite(i+j))
arr = [arr; i j]
end
end
end
arr
and I got this error message:
Output argument "bool" (and possibly others) not assigned a value in the
execution with "composite" function.
Error in untitled10 (line 6)
if and(composite(i), composite(j), composite(i+j))
I did make a composite function:
that run perfectly but when I put iteration numbers in it, it gives the error message before
function bool = composite(n)
for i = 2:n
for j = 2:n
if i*j == n
bool = true;
end
end
end
if n ==2
bool = false;
elseif n ==1
bool = false;
end
end
Thank you!
2 个评论
There are lots of values of n for which the output is not defined: 0, 3, 5, 7, ...
b = composite(7)
function bool = composite(n)
for i = 2:n
for j = 2:n
if i*j == n
bool = true;
end
end
end
if n ==2
bool = false;
elseif n ==1
bool = false;
end
end
Kenichi
2022-9-11
采纳的回答
function bool = composite(n)
bool = false; % Create a default value
if n > 2
for i = 2:n
for j = 2:n
if i*j == n
bool = true;
return; % No need for further tests
end
end
end
end
end
Your function composite() computes the same as the much faster Matlab function isprime() except for the input 2. The function composite can be improved: if e.g. i*j > n, the inner loop can be stopped by a break.
This command will fail at next, because Matlab's and() accept 2 inputs only.
if and(composite(i), composite(j), composite(i+j))
Maybe you mean
if composite(i) && composite(j) && composite(i+j)
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息
Translated by 
