_{}_{ }_{} _{} _{} _{}_{}

As rule traditional programming (Ñ, fortran,
Pascal and etc.) requires prior notice of a variable’ type that will be used in
a program. Programming in Mathcad does not require such notice. BASIC “dangles” between these two styles of
programming: who works with it he can solve himself to tell the variables *evidently*
by the special operator or to do it *implicitly* by the first assignation
the variable numerical or some other value. In the second case BASIC-programmer
can tell the type of a variable with help of suffix[1]:

- À! – real of single accuracy;
- À# – real of double accuracy;
- À% – integer-valued;
- À& – “long” integer-valued;
- À$ – textual.

If you programme in Mathcad it is worth to use this method. So the
problem of solution an ordinary differential equation (Cauchy problem) by
Runge-Kutta method of 4-th level is showed in the fig. 97.
All local variables have suffixes that mark their type: real, integer-valued,
textual.

The notice of the type of a variable with help
of suffix purposes two objects in traditional programming: saving of memory of
the computer and prompting for programmer about what the given variable has to
keep. Certainly in Mathcad with help of suffix of a variable we can succeed in
two object: variables with and without suffix in have one type – Variant in
Mathcad.

[1] Programmer can tell the type of the variable with help of prefix: int_A – integer-valued variable, real_A – real and etc.