what does == mean in script

hi im writing a piece of script for course work and would like comment each of the lines that i have used, could you help me and tell me what using == does when putting it into my script,

Thanks

Ben

N=-1:5;% sets the values on the x axis I want to use
x1=[1 2 2 1 4 0 0];
for n=1:7
  if n==1
      y1(1,n)=x1(1,n);
  else y1(1,n)=x1(1,n)+y1(1,n-1);
  end
end
stem(N,y1)

Answer 1

[Azzi Abdelmalek]

a==b

returns 1 if a and b are equal, it returns 0 if not. type

1==4 % check the result
4==4 % check the result

[Benjamin Garvin]

Thanks for your help Azzi

Answer 2

[Image Analyst]

It's used to compare two variables (numbers, arrays, etc.) and say whether they match or not. This is different than a single = sign, which is an assignment. In a==b you'll get a single true or false value, or an array of them if a and b are arrays. In a=b, you're taking the value of b and stuffing it into a, overwriting any prior value that a had, or creating a brand new variable a if no variable by that name existed yet.