How to update the value of the variable

clear
clc
syms forced velocityd densityd density dynamicviscosityd accelerationd Diameterd viscosityd Lengthd pressured a b c d y S Q x  f Lenght forced velocity density dynamic_viscosity acceleration Diameter viscosity S1 S2 S z z1 z2 pressure %variables
syms M L T temp
repeating_v1 = input('What do u want to know');
temp=repeating_v1;
density=66;
repeating_v1;
disp("Your" + temp+ "is"+ repeating_v1 )

I want the answer to be

Your density is 66 if the input was density

Answer 1

[drummer]

Try this workaround

clear
clc
syms forced velocityd densityd density dynamicviscosityd accelerationd Diameterd viscosityd Lengthd pressured a b c d y S Q x  f Lenght forced velocity density dynamic_viscosity acceleration Diameter viscosity S1 S2 S z z1 z2 pressure %variables
syms M L T temp
repeating_v1 = input('What do u want to know: \n');
temp=repeating_v1;
density=66;
if repeating_v1 == 'density' % Your condition: if input is density
    X = ['Your ' char(repeating_v1) ' is ' num2str(density)];
    disp(X);
end

Cheers