String array functions provided in C + +

The C + + language provides programmers with a number of functions that make it very easy to handle character arrays. These functions allow you to copy, concatenate, compare, and find the character array.

When an array is declared, C + + automatically produces a pointer to the first data element of the array. When you use the name of an array, you are actually using a pointer to the array.

Here are some of the string array functions provided in C + +, their prototypes and invocation statements, and the input of these functions is a character pointer (char*).

function prototype void strcat (char *dest, char *src);

Function: Concatenate the string src to the string dest behind.

Example:

Char s1[30]= "I love C + +";

Char s2[10]= "very much!";

strcat (S1,S2);

The data in S1 is "I love C + + very much"

function prototype void strcpy (char *dest, char *src);

Function: Copy the string src to the dest.

Example:

Char s1[30];

Char s2[30]= "I love C + +";

strcpy (S1,S2);

The data in S1 is "I love C + +"

function prototype int strcmp (char *s1,char *s2);

Function: Compares S1 and S2, returns 0 if equal, or returns a positive value if s1s2. Often in the if and while statements, or to sort words (alphabetically)

Example:

Char s1[15]= "Apple";

Char s2[15]= "Banana"

if (strcmp (S1, "Apple")) ==0; Check if S1 is Apple

if (strcmp (S1,S2) <0);//But S1 returns true before S2 in the alphabet

Function prototype char *strstr (char*,char*);

Function: Returns a pointer to the first occurrence of S2 in S1, or null if S1 does not contain S2

Example:

Char s1[50]= "The rain in Spain was mainly on the plan.";

Char s2[10]= "Elephant";

Char s3[10]= "Rain";

Char *char_ptr;

Char_ptr=strstr (S1,S2); Because no elephant,char_ptr is null in S1

Char_ptr=strstr (S1,S3); Char_ptr is the address in memory for R

function prototype int strlen (char*)

Function: Returns the length of the string, not including the null character

Example:

int length;

Char s1[25]= "I love c++!";

Length=strlen (S1); Length of 11

Function prototype Char *strncpy (char *dest,char *src,int N)

Function: Copy characters from SRC to dest

Example:

Char s1[10]= "abcdef"

strncpy (S1, "ABC", 3); The value of S1 is "ABCdef"

String array functions provided in C + +