When you're getting bored of programming, you can always ask why:
>> why A very rich programmer wanted it that way.
By placing a semicolon at the end of a line, you suppress the output. For example,
>> diag([1 2 3 4]) ans = 1 0 0 0 0 2 0 0 0 0 3 0 0 0 0 4 >> diag([2 4 6 8]);
If you do not assign the last result to anything, it is automatically assigned to the variable ans:
>> x = 3 + eye(2) x = 4 3 3 4 4 - 2*eye(2) >> ans = 2 4 4 2 >> ans + x ans = 6 7 7 6