Tip 97.
Type of a local variable of Mathcad
Fig. 97. Type of a local variable of Mathcad
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.