> For the complete documentation index, see [llms.txt](https://hyundai-robotics.gitbook.io/hi6-robot-language/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hyundai-robotics.gitbook.io/hi6-robot-language/rl-english/flowcontrol-subprogram/call-jump/param-return.md).

# 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 | <p>var x,y |

</p><p>x=5
</p><p>y=12.8
</p><p>call 105_dist2d,x,y
</p><p>var res=result()
</p><p>print res
</p><p>end
</p>                                          |
| 0105\_dist2d.job | <p># Calc. Euclide distance 2D
</p><p>param x,y
</p><p>var tmp
</p><p>
</p><p>tmp=x*x+y*y
</p><p>var len=sqr(tmp)  # distance from origin
</p><p>return len
</p> |
| 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.”&#x20;

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).


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