Diff: main.cpp

Revision:

0:27aceb51cedb

Child:

1:8a2fb22f43f3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Oct 03 16:15:01 2017 +0000
@@ -0,0 +1,41 @@
+/*
+Project: FunctionExample
+File: main.cpp
+
+ This simple program demonstrates that C passes arguments by value.
+ See http://www.csie.ntu.edu.tw/~r92094/c++/VT100.html for escape sequences.
+ 
+ Written by: Dr. C. S. Tritt; Last revised 10/3/17 (v. 1.0)
+*/
+#include "mbed.h"
+
+int myFunc(int x, int y); // Function declaration required.
+
+int main() {
+    while(true) {
+        const char ASCII_ESC=27; // Optional define escape for escape sequence.
+        printf( "%c[2J", ASCII_ESC ); // Optional VT100 clear screen escape seq.
+        printf("In function demo main...\n");        
+        int a = 5; // Create and initialize a.
+        printf("a = %d\n", a); // Display a.
+        int b = 6; // Create and initialize b.
+        printf("b = %d\n", b); // Display b.
+        printf("About to call my function.\n");
+        int c = myFunc(a, b); // Call my function.
+        printf("Function has returned.\n");
+        printf("a = %d\n", a); // Redisplay a.
+        printf("b = %d\n", b); // Redisplay b.               
+        printf("c = %d\n", c); // Display b.
+        wait(2.0f); // Pause for a second.
+    }
+}
+
+int myFunc(int x, int y) { // Function definition. Often in seperate files!
+    int z = x + y;
+    // Changing parameter values here won't change argument values in main!
+    x = 50;
+    printf("x = %d\n", x); // Generally don't put I/O in regular functions.
+    y = 100;
+    printf("y = %d\n", y); // Generally don't put I/O in regular functions.
+    return z; // Explicit return is required in C/C++. 
+}    
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