C + + string

C-style string

C-style strings originate from the C language and continue to be supported in C + +. The string is actually an array of one-dimensional characters terminated with the null character '% '. Therefore, a null-terminated string that contains the characters that make up the string.

The following declaration and initialization creates a "Hello" string. Because empty characters are stored at the end of the array, the size of the character array is one more than the number of characters in the word "Hello". ‘

Char greeting[6] = {'H'e'L  'l''o'  '};

Based on the array initialization rules, you can write the above statement as follows:

Char " Hello ";

The following is a memory representation of a string defined in C/s + +:

In fact, you do not need to put a null character at the end of a string constant. The C + + compiler automatically places ' \ ' at the end of the string when initializing an array. Let's try outputting the above string:

Instance:

#include <iostream>using namespacestd;intMain () {Chargreeting[6] = {'H','e','L','L','o',' /'}; cout<<"Greeting Message:"; cout<< Greeting <<Endl; return 0;}

When the above code is compiled and executed, it produces the following results:

Greeting Message:hello

There are a number of functions in C + + to manipulate null-terminated strings: supports a wide range of functions that manipulate null-terminated strings:

Serial Number	Functions & Purposes
1	strcpy (s1, S2); Copy the String s2 to the string S1.
2	strcat (s1, S2); The connection string S2 to the end of the string S1.
3	Strlen (S1); Returns the length of the string S1.
4	strcmp (s1, S2); If S1 and S2 are the same, then 0 is returned, if S1<S2 the return value is less than 0, if s1>s2 the return value is greater than 0.
5	STRCHR (s1, ch); Returns a pointer to the position of the first occurrence of the character ch in the string S1.
6	Strstr (s1, S2); Returns a pointer to the position of the first occurrence of the string S2 in the string s1.

The following example uses some of the above functions:

#include <iostream>#include<cstring>using namespacestd;intMain () {Charstr1[ One] ="Hello"; Charstr2[ One] =" World"; Charstr3[ One]; intLen; //copy str1 to STR3strcpy (STR3, str1); cout<<"strcpy (STR3, str1):"<< STR3 <<Endl; //connecting str1 and str2strcat (str1, str2); cout<<"strcat (str1, str2):"<< str1 <<Endl; //The total length of the str1 after the connectionLen =strlen (STR1); cout<<"strlen (str1):"<< Len <<Endl; return 0;}

When the above code is compiled and executed, it produces the following results:

10

C + + string