Are pointers really faster than arrays? How much do function calls slow things down? Is ++i faster than i = i + 1?Precise answers to these and many similar questions depend of course on the processor and compiler in use. If you simply must know, you'll have to time test programs carefully. (Often the differences are so slight that hundreds of thousands of iterations are required even to see them.For conventional machines, it is usually faster to march through large arrays with pointers rather than array subscripts, but for some processors the reverse is true. (Better compilers should generate good code regardless of which notation you use, though it's arguably easier for a compiler to convert array indices to pointers than vice versa .)Function calls, though obviously incrementally slower than in-line code, contribute so much to modularity and code clarity that there is rarely good reason to avoid them. (Actually, by reducing bulk, functions can improve performance.) Also, some compilers are able to expand small, critical-path functions in-line, either as an optimization or at the programmer's request.Before rearranging expressions such as i = i + 1, remember that you are dealing with a compiler, not a keystroke-programmable calculator. Any decent compiler will generate identical code for ++i, i += 1, and i = i + 1. The reasons for using ++i or i += 1 over i = i + 1 have to do with style, not efficiency.
C
Topic: Arrays
Are pointers really faster than arrays?
Browse random answers:
Do array subscripts always start with zero?
What will happen if in a C program you assign a value to an array element whose subscript exceeds the size of array?
What is the difference between null array and an empty array?
How to remove duplicate elements from an array?
Why is it necessary to give the size of an array in an array declaration?
Array is an lvalue or not?
Does mentioning the array name gives the base address in all the integers?
what will happen if we try to store more number of elements than specified in array size?
What is an array?
How to print 2 dimensional array in descending order?
What is Jagged Array?
Write a program to delete an element from an array?
Are arrays value types or reference types?
Assume you have an array that contains a number of strings (perhaps char * a[100]). Each string is a word from the dictionary. Your task, described in high-level terms, is to devise a way to determine and display all of the anagrams within the array (two words are anagrams if they contain the same characters; for example, tales and slate are anagrams.)
How can you sort the elements of the array in descending order?
What are the 3 different types of arrays?
When does the compiler not implicitly generate the address of the first element of an array?
Is it possible to have negative index in an array?
Difference between arrays and linked list?
Why is it necessary to give the size of an array in an array declaration?
What is an array of pointers?
What is an array of pointers?
Why is it necessary to give the size of an array in an array declaration?
Can the sizeof operator be used to tell the size of an array passed to a function?
How would you use qsort() function to sort the name stored in an array of pointers to string?
Are pointers really faster than arrays?
How can you sort the elements of the array in descending order?
How to find the row and column dimension of a given 2-D array?
Data structuresHow to distinguish between a binary tree and a tree?Allocating memory for a 3-D array#include "alloc.h"#define MAXX 3#define MAXY 4#define MAXZ 5main( ){int ***p, i, j, k ;p = ( int *** ) malloc ( MAXX * sizeof ( int ** ) ) ;for ( i = 0 ; i < MAXX ; i++ ){p[i] = ( int ** ) malloc ( MAXY * sizeof ( int * ) ) ;for ( j = 0 ; j < MAXY ; j++ )p[i][j] = ( int * ) malloc ( MAXZ * sizeof ( int ) ) ;}for ( k = 0 ; k < MAXZ ; k++ ){for ( i = 0 ; i < MAXX ; i++ ){for ( j = 0 ; j < MAXY ; j++ ){p[i][j][k] = i + j + k ;printf ( "%d ", p[i][j][k] ) ;}printf ( "\n" ) ;}printf ( "\n\n" ) ;}}
How does C compiler store elements in a multi-dimensional array?
Explain about Variably Dimensioned Arrays ?
Explain about Bit Arrays ?
