# C++ program to calculate frequency of characters in a string

## Calculating frequency of characters in a string.

In this article we will learn how to write a C++ program to calculate the frequency of characters in a string. First we have to find out unique characters from the string as calculating frequency means how many times each character is present in the string. We will use a for loop that will count how many times every unique character is present in the string. Then to print the result we will use another for loop. ## Algorithm:

• Initialize the variables.
• Accept the input.
• Initialize a for loop.
• This for loop will be used to count the number of time each character is present.
• Terminate first at the end of string.
• Initialize another for loop to print the frequency if it is at least 1.

## C++ programming code to calculate the frequency of characters in a string ```#include <iostream>
using namespace std;

int main()
{
//Initializing variables.
char str;
int i;
int freq = {0};

//Accepting inputs.
cout<<"Enter the string: ";
gets(str);

//Calculating frequency of each character.
for(i = 0; str[i] != '\0'; i++)
{
freq[str[i]]++;
}

//Printing frequency of each character.
for(i = 0; i < 256; i++)
{
if(freq[i] != 0)
{
cout<<"The frequency of "<<char(i)<<" is "<<freq[i]<<endl;
}
}
return 0;
}```
```Output:
Enter the string: prepinsta
The frequency of a is 1
The frequency of e is 1
The frequency of i is 1
The frequency of n is 1
The frequency of p is 2
The frequency of r is 1
The frequency of s is 1
The frequency of t is 1```

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