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Pointers - illustrative example 1
Pointers and references example from a Well House Consultants training course
More on Pointers and references [link]
Source code: excuse.c Module: C207
#include <stdio.h>
/* Adding a * after the variable type in a declaration sets up a pointer variable - a variable that holds the address of a value of the type given (the variable itself is always a memory address but it must know the type it points to. You can then prefix a variable of the appropriate type with "&" meaning address of - to store an address into the varaible, and you may prefix the varaible itself with "*" to mean "the contents of" - i.e. what it points at */ main () { int numbah; int * wherezit; numbah = 16; printf("Numbah is %d\n",numbah); wherezit = &numbah; printf("addy is %d\n",wherezit); printf("value is %d\n",*wherezit); } /* Sample Output: munchkin:c2 grahamellis$ ./excuse Numbah is 16 addy is 1606416940 value is 16 munchkin:c2 grahamellis$ Note - warning message at compile: munchkin:c2 grahamellis$ gcc -o excuse excuse.c excuse.c: In function ‘main’: excuse.c:22: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘int *’ munchkin:c2 grahamellis$ which comes because I'm handling an address as an integer as a demonstration of what goes on under the covers; it would normally be an error to tell the user an address! */ Learn about this subject
This module and example are covered on the following public courses:
* Learning to Program in C * Learning to program in C and C++ * Programming in C * C and C++ Programming * Learning to program in C and C++ * C and C++ Programming Also available on on site courses for larger groups Books covering this topic
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Other Examples
This example comes from our "Pointers and references" training module. You'll find a description of the topic and some
other closely related examples on the "Pointers and references" module index page.
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