>> h = 1.25creates a variable named ``h'' and assign value 1.25 to it. If there is already a variable named ``h'', then its value will be updated to 1.25.
The interpreter remembers the values of the variables, so that you can recall the names of the variables to use their values. For example:
>> c = 10; >> b = 8; >> sqrt(c^2 - b^2) 6
A variable name can be a string of letters and digits, and underscore _, but cannot begin with a digit. For example, x1, value_1, and _val03 are all valid variable names.