C + + string

C + + provides the following two types of string representations:

• C-style string
• String class types introduced by C + +

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.

Char greeting[6]={' H ',' E ',' l ',' l ',' O ', ' n '};                 

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

Char greeting[]="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.

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); Returns 0 if S1 and S2 are the same, if S1<s2 returns less than 0 if S1>S2 returns 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 String class in C + +

The C + + standard library provides the string class type, supports all of the above operations, and adds additional functionality.

The String class provides a series of operations against strings, such as:

• 1. Append ()--adding characters at the end of a string
• 2. Find ()--Find the string in the string
• 4. Insert ()--insertion character
• 5. Length ()--Returns the lengths of the strings
• 6. Replace ()--replace string
• 7. substr ()--Return a substring

C + + string