Tutorial

Using the puts() function in C/C++

Published on August 3, 2022

By Sneh

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Introduction

Hello reader! Today in this tutorial we are going to discuss about the vastly used puts() function in for both C and C++ programming languages.

Even though the printf() and cout functions in both C and C++ are prominent for printing variables, numbers, lines, etc. they ultimately lack behind while printing strings especially printf(). The puts() function comes handy in that case.

The puts() function in C/C++

The puts() function in C/C++ is used to write a line or string to the output(stdout) stream. It prints the passed string with a newline and returns an integer value. The return value depends on the success of the writing procedure.

The puts() function declaration is given below.

int puts(const char* str);

Here, str is the constant string that is to be printed.

Let us look at a small example.

#include<stdio.h>
int main()
{
	//string initialisation
    char Mystr[] = "C and C++";
    
    puts(Mystr); //writing the string to stdout
    
    return 0;
}

Output:

C and C++

As you can see, our string Mystr has been successfully printed to the stdout. The below-given code snippet also yields the same output in C++.

#include<iostream>
using namespace std;
int main()
{
	//string initialisation
    char Mystr[] = "C and C++";
    
    puts(Mystr); //writing the string to stdout
    
    return 0;
}

Using the puts() function in C/C++

We have mentioned earlier, that the puts() function appends a newline character at the end while writing a string/line.

#include<stdio.h>
int main()
{
	//string initialisation
    char Mystr1[10] = "Python";
    char Mystr2[10] = "Kotlin";
    
    puts(Mystr1);
    puts(Mystr2); //not specifically adding a newline
    
    return 0;
}

Output:

Python
Kotlin

Here, we have initialized two strings Mystr1 and Mystr2. While printing these strings using the puts() method in either C or C++, we do not need to particularly add a "\n"(newline) as the function already appends one.

puts() return value

The puts() function returns an non-negative integer number for successful execution. Otherwise returns EOF for any error.

The below-given example illustrates the return value for the puts() function.

#include<stdio.h>
int main()
{
	//string initialisation
    char Mystr[] = "The puts() function";
    
    int val = puts(Mystr);
    printf("Returned Value Val = %d", val);
    
    return 0;
}

Output:

The puts() function
Returned Value Val = 0

puts() VS fputs() functions in C/C++

As we have learned earlier, the puts() function writes a line or string to the stdout stream. Whereas, the fputs() function is used to write to any stream or a file. Hence, the biggest difference between the two functions is the fact that with fputs(), the user can specify the stream to which he/she wants to write.

Moreover, the fputs() function doesn’t append a newline character("\n")at the end of the passed string/line.