# C program to find the length of a string

• Difficulty Level : Basic
• Last Updated : 24 Jun, 2022

Given a string str. The task is to find the length of the string.

Examples

```Input: str = "Geeks"
Output: Length of Str is : 5

Input: str = "GeeksforGeeks"
Output: Length of Str is : 13```

In the below program, to find the length of the string str, first the string is taken as input from the user using scanf in , and then the length of Str is calculated using and using method .
Below is the C program to find the length of the string.
Example 1: Using loop to calculate the length of string.

## C

 `// C program to find the length of string``#include ``#include ` `int` `main()``{``    ``char` `Str[1000];``    ``int` `i;` `    ``printf``(``"Enter the String: "``);``    ``scanf``(``"%s"``, Str);` `    ``for` `(i = 0; Str[i] != ``'\0'``; ++i);` `    ``printf``(``"Length of Str is %d"``, i);` `    ``return` `0;``}`

Output:

```Enter the String: Geeks
Length of Str is 5```

Time Complexity: O(N)

Auxiliary Space: O(1)

Example 2: Using strlen() to find the length of the string.

## C

 `// C program to find the length of``// string using strlen function``#include ``#include ` `int` `main()``{``    ``char` `Str[1000];``    ``int` `i;` `    ``printf``(``"Enter the String: "``);``    ``scanf``(``"%s"``, Str);` `    ``printf``(``"Length of Str is %ld"``, ``strlen``(Str));` `    ``return` `0;``}`

Output:

```Enter the String: Geeks
Length of Str is 5```

Time Complexity: O(1)

Auxiliary Space: O(1)

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