Activity 1.4.
Can you name a variable "cos"? If so, what is the effect of doing so?
Section 1.7 Scalar Variables
Variables need not be declared in MATLAB, one simply makes an assignment.
>> x = 5; >> y = 10; >> z = x + y;
When variable are assigned, they show up in the workspace window, along with their value and class (built-in debugger!)
>> x = 10; y = 10; >> z = x + y;
Subsection 1.7.1 Naming Variables
Rules for variable names (similar to C):
- Can contain only letters, digits, and the underscore ’_’
- Must begin with a letter (not true for C, e.g., _var)
- Case sensitive (AA Aa aA aa are all different variables)
- Avoid using built-in function names. You can actually use such a name, but then you can no longer use the function (i.e. cos, sin, exp, sqrt, etc.)
- Can be up to 63 characters long… but we know that using such a variable name would be poor style!
Subsection 1.7.2 Managing Variables
| Function | Description |
clear |
Removes all variables from memory |
clear x y z |
Removes only the variables x, y, z
|
who |
Displays a list of variables in memory |
whos |
Displays a list of variables in memory, along with their size and other info |
The Workspace Window also shows you a visual picture of the variables that you have assigned.
