3.7.2 Parameters and param, return

In a job program, formal parameters are used as channels through which input and output are passed. The param statement will define formal parameters at the beginning of the job program.

In the following example, job no. 105 is named as "dist2d,” as it is a subjob that acquires the Euclidean distance from the origin to the coordinate value (x, y) and returns it to len.

0001.job	var x,y x=5 y=12.8 call 105_dist2d,x,y var res=result() print res end
0105_dist2d.job	# Calc. Euclide distance 2D param x,y var tmp tmp=x*x+y*y var len=sqr(tmp) # distance from origin return len
Result	13.742

In job no. 1, the dist2d subprogram is called with the call statement, and “x, y,” which are local variables, are passed. In the dist2d subprogram, “ldX,” and “ldY” defined with the param statement are called “formal parameters,” and “x, y” passed to the call statement are called “actual parameters.”

The dist2d program transports resulting values to external destinations through return statements. Returned values can be obtained by calling a result() function in the called program.

(A return statement and an end statement have the same action as they end a called program and return to the main program. However, a return statement is different from an end statement as the former can designate a resulting value as an element).