Count the number of null elements in an array in C++
In this tutorial, we will learn how to count the null elements in the string array in C++.
There is no predefined string data type in C because of which in order to create a string we have to use a character array.
So to make an array of strings, we have to make use of a 2-dimensional array(matrix) where each row holds different strings in that matrix.
C++ overcomes this drawback of C language because of a predefined class called “string” in C++. Using this string class, we can create objects to store string data types and use them very efficiently. (Note:- String is not a primary data type.)
Null elements are those elements of a string array that do not contain any character within the double-quotes. For eg,
#include<iostream> #include<string.h> using namespace std; int main() { string s[] = {"There is a null element","after","this",""}; return 0; }
Here the last element of the array ‘s’ i.e. s[3] is a null element as it contains no characters within the double-quotes.
Counting Null Elements using C++ for loop
The basic approach is to access each element of string from start to end. Increment a pre-initialized counter by ‘1’ whenever a null element is encountered.
#include <iostream> #include <string.h> using namespace std; int main() { int count = 0; // Counter initialized to zero string s1[7] = {"India","is","","my","","","country"}; // Defined a string array 's1' of size 7 for(int i=0; i<7; i++) { if(s1[i]=="") count++; // Whenever a null element is encountered increment the counter } cout<<"Number of null elements in s1 are: "<<count; // Output the counter value on the screen return 0; }
The output for the above program is,
Number of null elements in s1 are: 3
Comment for any queries.
Thank You!
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