Seven program modules form part of a program. A description of the relationship between the modules is summarised below. Any return values are stated in the description. Module name | Description ---|--- Mod-A | calls Mod-B followed by Mod-C Mod-B | • called with parameters Par1 and Par2 • calls either Mod-D or Mod-E, determined when the program runs • returns a Boolean value Mod-C | • called with parameters Par1 and Par3 • Par3 is passed by reference • repeatedly calls Mod-F followed by Mod-G Mod-D | called with parameter Par2 Mod-E | • called with parameter Par3 • returns an integer value Mod-F | called with parameter Par3 Mod-G | • called with parameter Par3 • Par3 is passed by reference Parameters in the table are as follows: : Par1 and Par3 are of type string. Par2 is of type integer.

1. (a)(i)Identify the modules that would be implemented as functions.[1]
2. (a)(ii)Modules Mod-F and Mod-G are both called with Par3 as a parameter. In the case of Mod-F, the parameter is passed by value. In the case of Mod-G, the parameter is passed by reference. Explain the effect of the two different ways of passing the parameter Par3.[2]
3. (b)Draw a structure chart to show the relationship between the seven modules and the parameters passed between them. [Figure 7.1][6]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.