C++ String Manipulation

C++ code to count digits in a string

C++ programming language also provides a function called isdigit(int) that can be used to indicate whether a character in a string is a digit. This function takes one argument--the character(presented by its ascii value) that you want to check. In the example below we use the isdigit(int) function to count the number of digits in a string "C++ programming2011".


#include <cstdlib>
#include <iostream>
#include <conio.h>
#include <cmath>

using namespace std;

void countDigits(){
  string st="C++ programming2011";
  int count=0;
  for(int i=0;i<st.size();i++)
     if(isdigit(st[i])) count++;
  cout<<"Number of digits:"<<count;


int main(){

return 0;


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