C - Function const Parameters

Introduction

You can qualify a function parameter using the const keyword.

It indicates that the function will treat the argument that is passed as a constant.

Because arguments are passed by value, using const is only useful when the parameter is a pointer.

Here's an example of a function with a const parameter:

bool test(const char* pmessage)
{
  return true;
}

The type of the parameter, pmessage, is a pointer to a const char.

It's the char value that's const, not its address.

The following code uses functional approach to string sorting.

Related Topics

• Passing a value to a function
• Passing constant values to a function
• Passing multiple values to a function
• Checking value passed into a function
• Passing an array to a function
• Using function to change array element value
• Passing a pointer to a function

Exercise

• Write program to create function to change float value via pointer
• Write program to create function to initialize and print array content

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