Site icon Learn C++

Learn to Use Strings in C++

In C programming language ASCII codes are used as in char arrays to store texts in ASCII mode. You can use char arrays in both C and C++, they are faster in operations and they have less memory usage. In s modern way, strings are useful for storing texts and they are defined in the string library. A string class contains a collection of characters surrounded by double quotes as we used in char arrays.

A string variable can be assigned as below,

[crayon-67428ec7c7a02935330642/]

Here is the full C++ example that shows how to print out a string to screen,

[crayon-67428ec7c7a0c488426699/]

and the output will be,

[crayon-67428ec7c7a0e715473175/]

 

1. Reading and Modifying Characters of a string

strings are used like char arrays, you can reach each character by using [ ] brackets and the index number. See example below

[crayon-67428ec7c7a13768921192/]

or you can use std in namespace so you don’t need to use std:: in each std commands as below,

[crayon-67428ec7c7a15557850478/]

output will be second character as below,

[crayon-67428ec7c7a19758665514/]

Note that index numbers in C and C++ starts with 0, and str[0] is ‘T’ character. We can modify character of a string as below,

[crayon-67428ec7c7a1b498423595/]

String Concatenation

strings are easy to operate with them in many ways, while we use strcat(), strcpy() functions in char arrays.

[crayon-67428ec7c7a1d254210956/]

strings are classes with many features, this is why they are preferred in modern C++. For example you can add another string by using its append() function.

[crayon-67428ec7c7a1f202695347/]

this is same as

[crayon-67428ec7c7a21458070888/]

Length of a string

Length of string, number of characters can be obtained by using it’s length() command as below,

[crayon-67428ec7c7a25504967272/]

Size of a string

Size of string is size of string in the memory, if characters has 1 byte in compiler option this will equal to length, if characters has 2 bytes it will have double size of its length.

[crayon-67428ec7c7a26480453740/]

Note that, in C++ Builder both string and String are used in same ways. In the last C++ Builder versions Strings are UnicodeString, supports globally and operations are explained before in Unicode Strings in C++ On Windows

Exit mobile version