Pointer to Constants

Q

What is the difference between const char* p and char const* p?

✍: FYIcenter

A

In const char* p, the character pointed by "p" is constant, so you can not change the value of character pointed by p but u can make "p" refer to some other location.

In char const* p, the pointer "p" is constant not the character referenced by it, so you can not make "p" to refernce to any other location but u can chage the value of the char pointed by "p".

2007-02-26, 6746👍, 0💬

Bitwise Operations
Which bit wise operator is suitable for turning off a particular bit in a number? The bitwise AND operator. Here is an example: enum { KBit1 = 0x00000001 KBit2 = 0x00000010, KBit3 = 0x00000100, ... }; some_int = some_int & ~KBit24; 2007-02-26, 9835👍, 0💬

Convert an integer or a float to a string
Does there exist any other function which can be used to convert an integer or a float to a string? Some implementations provide a nonstandard function called itoa(), which converts an integer to string. char *itoa(int value, char *string, int radix); DESCRIPTION - The itoa() function constructs a s... 2007-02-26, 8584👍, 0💬

Bitwise Operations
Which bit wise operator is suitable for checking whether a particular bit is on or off? The bitwise AND operator. Here is an example: enum { KBit1 = 0x00000001 KBit2 = 0x00000010, KBit3 = 0x00000100, ... }; if ( some_int & KBit24 ) printf("Bit number 24 is ON\n"); else printf("Bit number 24 is O... 2007-02-26, 8136👍, 0💬

Bitwise Operations
Which bit wise operator is suitable for turning on a particular bit in a number? The bitwise OR operator. In the following code snippet, the bit number 24 is turned ON: enum { KBit1 = 0x00000001 KBit2 = 0x00000010, KBit3 = 0x00000100, ... }; some_int = some_int | KBit24; 2007-02-26, 7600👍, 0💬

malloc Function
Why does malloc(0) return valid memory address? What's the use? malloc(0) does not return a non-NULL under every implementation. An implementation is free to behave in a manner it finds suitable, if the allocation size requested is zero. The implmentation may choose any of the following actions: * A... 2007-02-26, 7117👍, 0💬

Including Source Files
What is the result of using Option Explicit? When writing your C program, you can include files in two ways. The first way is to surround the file you want to include with the angled brackets < and >. This method of inclusion tells the preprocessor to look for the file in the predefine... 2007-02-26, 7064👍, 0💬

Pointer to Constants
What is the difference between const char* p and char const* p? In const char* p, the character pointed by "p" is constant, so you can not change the value of character pointed by p but u can make "p" refer to some other location. In char const* p, the pointer "p" is constant not the character refer... 2007-02-26, 6747👍, 0💬

Calling Base Class Methods
How can method defined in multiple base classes with same name be invoked from derived class simultaneously? class x { public: m1(); }; class y { public: m1(); }; class z: public x, public y { public: m1() { x::m1(); y::m1(); } }; 2007-02-26, 6572👍, 0💬

Opening Files to Share with Other Programs
How can I open a file so that other programs can update it at the same time? Your C compiler library contains a low-level file function called sopen() that can be used to open a file in shared mode. Beginning with DOS 3.0, files could be opened in shared mode by loading a special program named SHARE... 2007-02-26, 6428👍, 0💬

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