In C, the **`strtok()` function** is used to split a string into a series of tokens based on a particular delimiter. A token is a substring extracted from the original string.

# Syntax
The general syntax for the `strtok()` function is:


char *strtok(char *str, const char *delim)

## Parameters
Let's look at the parameters the `strtok()` function takes as input:

* `str`: The string which is to be split
* `delim`: The character on the basis of which the split will be done

## Return value
The function performs one split and returns a pointer to the token split up. A null pointer is returned if the string cannot be split. 

# Example
Let's start off by a simple example!

## 1. Extracting a single token

The following piece of code will just split up the `Hello world` string in two and will return the first token extracted from the function.


#include<stdio.h>
#include <string.h>

int main() {
 char string[50] = "Hello world";
 // Extract the first token
 char * token = strtok(string, " ");
 printf( " %s\n", token ); //printing the token
 return 0;
}

## 2. Extracting all possible tokens
To find all possible splits of the string, based on a given delimiter, the function needs to be called in a loop. See the example below to see how this works.

Let's see how we can split up a sentence on each occurrence of the white space character:

#include<stdio.h>
#include <string.h>

int main() {
 char string[50] = "Hello! We are learning about strtok";
 // Extract the first token
 char * token = strtok(string, " ");
 // loop through the string to extract all other tokens
 while( token != NULL ) {
 printf( " %s\n", token ); //printing each token
 token = strtok(NULL, " ");
 }
 return 0;
}

> **Note:** The `strtok()` function also modifies the original string. The original string is truncated to the first token. 

#include<stdio.h>
#include <string.h>

int main() {
 char string[50] = "Hello world";
 printf( "Original string: %s\n", string ); //printing the string
 // Extract the first token
 char * token = strtok(string, " ");
 printf( " %s\n", token ); //printing the token
 printf( "String after strtok(): %s\n", string ); //printing the string
 return 0;
}

Splits a string into smaller tokens based on a delimiter


What does the `strtok()` function do in C?

What does the <code>strtok()</code> function do in C?

It always returns a pointer to the first character of the input string

It modifies the original string by replacing delimiters with null characters temporarily

Which of the following is true about `strtok()`?

Which of the following is true about <code>strtok()</code>?

Because it only accepts null-terminated strings

Because it is designed to work with single-threaded applications only

Because it internally maintains a static pointer to the next token within the string being tokenized

Because it has limitations in tokenizing strings with multiple delimiters

Why is `strtok()` not considered thread-safe?

Why is <code>strtok()</code> not considered thread-safe?

Splitting a string using strtok() in C

strtok() in C splits a string into tokens based on a delimiter, modifying the original string and lacking thread-safety.

Splitting a string using strtok() in C

Syntax

Parameters

Return value

Example

1. Extracting a single token

2. Extracting all possible tokens

Characteristics and limitations of `strtok()`

Test your knowledge !

Splitting a string using strtok() in C

Syntax

Parameters

Return value

Example

1. Extracting a single token

2. Extracting all possible tokens

Characteristics and limitations of strtok()

Test your knowledge !

Characteristics and limitations of `strtok()`