Arrays of Char VS C Strings

Action Array of char String

Declare variable: char array [5]; char cstr [5]; // stores only 4 chars of a string

Declare variable char array [5] = { 'A', 'B', 'C', 'D', 'E' }; char cstr [5] = "ABCD";

and initialize: or char cstr[5] = { 'A', 'B', 'C', 'D', '\0' };

or char array [] = { 'A', 'B', 'C', 'D', 'E' }; or char cstr [] = "ABCD";

or char cstr[5] = { 'A', 'B', 'C', 'D', '\0' };

Print first char: cout << array[0]; cout << cstr[0];

Print all chars: for (n = 0; n < 5; n++) cout << cstr;

cout << array[n]; or for (n = 0; cstr[n] != '\0'; n++)

cout << cstr[0];

Read first char: cin >> array[0]; cin >> cstr[0];

or array[0] = cin.get(); or cstr[0] = cin.get();

or cin.get(array[0]); or cin.get(cstr[0]);

Read all chars: for (n = 0; n < 5; n++) cin >> cstr; // reads up to whitespace

cin >> array[n]; or for (n = 0; n < 4; n++)

cin >> cstr[n];

cstr[n] = '\0';

Assign first char char ch; char ch;

to another variable: ch = array[0]; ch = cstr[0];

Assign all chars char copy [5]; char copy [5];

to another for (n = 0; n < 5; n++) strcpy (copy, cstr);

variable: copy [n] = array [n]; or strcpy (copy, "CSCI");

or // same as for the array of char

Comparison: strcmp (cstr, copy)

returns a value less than 0 if cstr < copy

or a value of 0 if cstr == copy

or a value greater than 0 if cstr > copy

Test for equality: equal = true; if ( strcmp (cstr, copy) == 0 ) ...

for (n = 0; n < 5; n++)

if (array[n] != copy[n])

{

equal = false;

break;

}

String Operations found in C++ library <cstring>

Operation Description

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strcat (s1, s2) Appends s2 to s1

strncat (s1, s2, n) Appends at most n characters of s2 to s1

strcy (s1, s2) Copies s2 into s1

strncpy (s1, s2, n) Copies first n charcters of s2 into s1

strlen (s) Returns length of s (not counting the terminating null character)

strcmp (s1, s2) Compares s1 with s2 and returns an integer less than, equal to,

or greater than 0 according to whether s1 is less than, equal to,

or greater than s2

strncmp (s1, s2, n) Same as strcmp, but compares only the first n characters of s1 and s2

strchr (s, c) Returns a pointer to the first occurrence of c (character) in s, or NULL if not found

strrchr (s, c) Like strchr but locates the last occurrence of c in s

strstr (s1, s2) Returns a pointer to the first occurrence in s1 of s2, or NULL if not found

strpbrk (s1, s2) Returns a pointer to the first occurrence in s1 of any character of s2, or NULL if not found

strspn (s1, s2) Returns the number of characters in s1 before any character in s2

strcspn (s1, s2) Returns the number of characters in s1 before a character not in s2

String Operations found in C++ library <cstdlib>

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double atof (s) Returns the value obtained by converting the character string s to double

int atoi (s) Returns the value obtained by converting the character string s to int

long atoll (s) Returns the value obtained by converting the character string s to long int