Matlab 中的 For 循环定义

Question

I'm new to the Matlab. Can anyone explain for me why:

If a for loop starts with for i = 1:0, then the body can only execute once.

Thank you.

Answer 1

If you do not mention the step increment/decrement in for loop in MATLAB by default it will always take it as increment by 1. For example

for i=1:3
disp(i)
end

It will print i three times ie 1 2 3

For below example it will print nothing as condition already becomes false

for i=1:0
disp(i)
end

For step more than 1 or negative increment (decrement) you have to mention it explicitly as shown below

for i=1:2:6
disp(i)
end

it will print 1 3 5

or

for i=1:-1:0
disp(i)
end 

It will print 1 0

Answer 2

Try typing 1:0 in the command window. The result will be "1×0 empty double row vector", which means this is an empty vector. Perhaps what you were trying to achieve is the vector [1,0]. In this case, you should write explicitly i = 1:-1:0 , which yields the correct result.