Symbolic Variables and expressions:
The MATLAB has a type known as sym for the symbolic variables and expressions; these work with strings. The illustration, to generate a symbolic variable a and execute the addition, at first a symbolic variable would be generated by passing the string 'a' to the sym function:
>> a = sym('a');
>> a+a
ans =
2*a
Also the Symbolic variables can store expressions. For illustration, the variables b and c store symbolic expressions as:
>> b = sym('x^2');
>> c = sym('x^4');