Tutorials:Pointers - Revision history

Dark Byte: Undo revision 6804 by TheyCallMeTim13 (talk) In is correct here

2019-05-06T12:06:56Z

Undo revision 6804 by TheyCallMeTim13 (talk) In is correct here

TheyCallMeTim13 at 23:48, 5 May 2019

2019-05-05T23:48:10Z

TheyCallMeTim13 at 23:44, 5 May 2019

2019-05-05T23:44:40Z

TheyCallMeTim13 at 23:44, 5 May 2019

2019-05-05T23:44:04Z

TheyCallMeTim13 at 10:23, 21 April 2018

2018-04-21T10:23:26Z

TheyCallMeTim13 at 10:23, 21 April 2018

2018-04-21T10:23:08Z

TheyCallMeTim13 at 04:56, 18 April 2018

2018-04-18T04:56:12Z

TheyCallMeTim13 at 03:11, 7 February 2018

2018-02-07T03:11:13Z

FreeER: /* Objects in memory */

2018-02-06T02:12:55Z

‎Objects in memory

FreeER at 02:09, 6 February 2018

2018-02-06T02:09:59Z

@@ Line 14: / Line 14: @@
 : QWORD : ''int64/long''
-If programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
+In programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
 In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays, and they use a [https://en.wikipedia.org/wiki/Null-terminated_string Null-terminated] format.

@@ Line 38: / Line 38: @@
 ** '''[Process.exe+123ABC]+18''' : ''integer'' : DWORD - Coins value.
 ** '''[Process.exe+123ABC]+1C''' : ''pointer'' : DWORD - Pointer to where the Coordinates object is stored in memory.
-*** '''[[Process.exe+123ABC]+20]+10''' : ''float'' : DWORD - X coordinate.
+*** '''[[Process.exe+123ABC]+1C]+10''' : ''float'' : DWORD - X coordinate.
-*** '''[[Process.exe+123ABC]+20]+14''' : ''float'' : DWORD - Z coordinate.
+*** '''[[Process.exe+123ABC]+1C]+14''' : ''float'' : DWORD - Z coordinate.
-*** '''[[Process.exe+123ABC]+20]+18''' : ''float'' : DWORD - Y coordinate.
+*** '''[[Process.exe+123ABC]+1C]+18''' : ''float'' : DWORD - Y coordinate.
-** '''[Process.exe+123ABC]+24''' : ''pointer'' : DWORD - Pointer to where the Inventory array starts in memory.
+** '''[Process.exe+123ABC]+20''' : ''pointer'' : DWORD - Pointer to where the Inventory array starts in memory.
-*** '''[[Process.exe+123ABC]+24]+XX*4''' : ''pointer'' : DWORD - Pointer to where the inventory array item number XX is stored in memory.
+*** '''[[Process.exe+123ABC]+20]+XX*4''' : ''pointer'' : DWORD - Pointer to where the inventory array item number XX is stored in memory.
-**** '''[[[Process.exe+123ABC]+24]+XX*4]+4''' : ''integer'' : DWORD - The inventory item Count value.
+**** '''[[[Process.exe+123ABC]+20]+XX*4]+4''' : ''integer'' : DWORD - The inventory item Count value.
-**** '''[[[Process.exe+123ABC]+24]+XX*4]+8''' : ''pointer'' : DWORD - Pointer to where item object is stored in memory.
+**** '''[[[Process.exe+123ABC]+20]+XX*4]+8''' : ''pointer'' : DWORD - Pointer to where item object is stored in memory.

@@ Line 14: / Line 14: @@
 : QWORD : ''int64/long''
-In programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
+If programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
 In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays, and they use a [https://en.wikipedia.org/wiki/Null-terminated_string Null-terminated] format.

← Older revision		Revision as of 23:44, 5 May 2019
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−	Pointers are integers who's size is the base word size of the process and store an address in that process. That is in a 16 bit process a pointer is a WORD (16 bit), in a 32 bit process a pointer is a DWORD (32 bit), and in a 64 ~~but~~ process a pointer is a QWORD (64 bit).	+	Pointers are integers who's size is the base word size of the process and store an address in that process. That is in a 16 bit process a pointer is a WORD (16 bit), in a 32 bit process a pointer is a DWORD (32 bit), and in a 64 bit process a pointer is a QWORD (64 bit).

	; 16 bit		; 16 bit

@@ Line 16: / Line 16: @@
 In programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
-In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays, and they use a [https://en.wikipedia.org/wiki/Null-terminated_string Null-terminated] format
+In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays, and they use a [https://en.wikipedia.org/wiki/Null-terminated_string Null-terminated] format.
 ==== Objects in memory ====

@@ Line 10: / Line 10: @@
 : WORD : ''int16/short''
 ; 32 bit
-: WORD : ''int32/int''
+: DWORD : ''int32/int''
 ; 64 bit
-: WORD : ''int64/long''
+: QWORD : ''int64/long''
 In programs and programming simply using only integers and floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.

@@ Line 63: / Line 63: @@
-But if we had an Actor object that held all the values, and then a Player object that inherits from Actor, a Player object could get assembled some thing like this:
+But if we had a Player object that contains an Actor object, it might get assembled some thing like this in a 32bit process:
 * '''Process.exe+123ABC''' : ''pointer'' : DWORD - Player base.
 ** '''[Process.exe+123ABC]+4''' : ''pointer'' : DWORD - Actor base.
@@ Line 71: / Line 71: @@
 *** '''[[Process.exe+123ABC]+4]+18''' : ''integer'' : DWORD - Coins value.
 *** '''...'''
 And the more complex the object structure the more complex the pointer structure.
 ==== Example of multi-level pointers ====

@@ Line 14: / Line 14: @@
 : WORD : ''int64/long''
-In programs and programming simply using integers, floating point values, and strings really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name.
+In programs and programming simply using integers, floating point values really isn't feasible with complex objects. So the concept of an object in memory was seen as a must. This is where pointers come in. They simply point to an object in memory, hence the name. Even strings are implemented with pointers to the series of characters in memory, though most high-level languages don't make you aware of that fact.
-Technically strings are pointers to character arrays, that end with a null byte (0x0). In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays.
+In the [https://en.wikipedia.org/wiki/ANSI_C ANSI C] there is no string type just character arrays, and they'd better have a 0x0 / NUL / NULL byte after all the characters if you want to use them with any standard library function!
 ==== Objects in memory ====