C++ Program to find number of digits in an integer
Finding number of digits in an integer in C++
Here we will discuss how to find the number of digits in an integer in c++ programming language.
An integer is made up a number of digits i.e. a number is a combination of 0-9. Example 9825 is any integer which has 4 digits.
Method Discussed :
- Method 1 : Using loop
- Method 2 : Using formulae.
Let’s discuss above two methods in brief,
Method 1:
Let’s see how the code works:
- The user will give an input.
- The input will be stored in an int type variable say num.
- do while loop is started
- Divide num by 10 and store result in num itself
num=num/10;
- Every time num is divided by 10 increment digit by 1
digit++;.
- Do this until num is not equal to 0
while(num!=0);
- digit is printed which is the number of digits in num.
Method 1 : Code in C++
Run
#include<bits/stdc++.h>
using namespace std;
int main(){
int num = 20901;
int digit = 0;
while(num>0){
digit++;
num = num/10;
}
cout<<"No. of digits = "<< digit;
}
Output
No. of digits = 5
Method 2 :
In this method we will simple use the mathematical formulae,
- No. of digits : floor(log10(n))+1
Method 2 : Code in C++
Run
#include<bits/stdc++.h>
#include<iostream>
using namespace std;
int
main ()
{
int num = 20901;
int digit = floor (log10 (num)) + 1;
cout << "No. of digits = " << digit;
}
Output
No. of digits = 5
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string N;
cin>>N;
int s=N.length();
cout<<"size of integer N is "<<s<<endl;
}