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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-67ea8a4902d26257118878/]

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

[crayon-67ea8a4902d30007378666/]

and the output will be,

[crayon-67ea8a4902d34283302334/]

 

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-67ea8a4902d37242073281/]

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

[crayon-67ea8a4902d39861195716/]

output will be second character as below,

[crayon-67ea8a4902d3a177571370/]

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-67ea8a4902d3e294065118/]

String Concatenation

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

[crayon-67ea8a4902d40060722042/]

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-67ea8a4902d42748705397/]

this is same as

[crayon-67ea8a4902d44518588494/]

Length of a string

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

[crayon-67ea8a4902d45004811019/]

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-67ea8a4902d47761426369/]

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

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