Turning for outputs into a row vector

I need to get all of the outputs of b into a row vector size [1 5] so b=[4,1,0,1,4]

for a=-2:2
    b=a.^2
end

Outputs are

b=4
b=1
b=0
b=1
b=4

I tried

for a=-2:2
    b(a)=a.^2
end

I got, Array indices must be positive integers or logical values. So then I tried

for a=-2:2
    b(1:a)=a.^2
end

But I did not get what I wanted.

[VBBV]

x = 1;
for a=-2:2
    b(x)=a^2;
    x = x+1;
end
b

b = 1×5

4 1 0 1 4

Try this, But as @KSSV suggested, no loop needed

Answer 1

[KSSV]

a = -2:2 ; 
for i = 1:length(a)
    b(i)=a(i).^2
end

No Loop needed:

a = -2:2 ; 
b = a.^2 ;