## 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.

[1] Programmer can tell the type of the variable with help of prefix: int_Ainteger-valued variable, real_Areal and etc.