C++ program to find the number of consonants in a string

Here is a program to find the number of consonants in a string in C++. I given 5 different ways you can find the number of consonants in a string like using switch-case, if-else ladder, function, recursion etc.  

Method 1 : C++ program to find number of consonants in given string using array

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{

    char str[20],vowels[]={'a','e','i','o','u','A','E','I','O','U'};
    int flag=0,consonants=0;
    cout<<"Enter the string ";
    gets(str);
    for(int i=0;str[i]!='\0';i++)
    {
        if(str[i]>'z'||str[i]<'A'||(str[i]>'Z'&&str[i]<'a'))
            continue;
        for(int y=0;y<10;y++)
            if(str[i]==vowels[y])
               flag=1;
        if(flag!=1)
            consonants++;
        flag=0;
    }
    cout<<"Number of consonants "<<consonants;
    return 0;
}

Method 2 : C++ program to find number of consonants in given string using if-else ladder

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{

    char str[20];
    int consonant=0;
    cout<<"Enter the string ";
    gets(str);
    for(int i=0;str[i]!='\0';i++)
    {
        if(str[i]>'z'||str[i]<'A'||(str[i]>'Z'&&str[i]<'a'))
            continue;
        else if(str[i]=='a'||str[i]=='A')
            continue;
        else if(str[i]=='e'||str[i]=='E')
            continue;
        else if(str[i]=='i'||str[i]=='I')
            continue;
        else if(str[i]=='o'||str[i]=='O')
            continue;
        else if(str[i]=='u'||str[i]=='U')
            continue;
        else
            consonant++;
    }
    cout<<"Number of consonant "<<consonant;
    return 0;
}

Method 3 : C++ program to find number of consonants in given string using function

#include<iostream>
#include<stdio.h>
using namespace std;
int countc(char *str)
{
    int consonant=0;
    for(int i=0;str[i]!='\0';i++)
    {
         if(str[i]>'z'||str[i]<'A'||(str[i]>'Z'&&str[i]<'a'))
            continue;
        if(str[i]=='a'||str[i]=='e'||str[i]=='i'||str[i]=='o'||str[i]=='u'
           ||str[i]=='A'||str[i]=='E'||str[i]=='I'||str[i]=='O'||str[i]=='U')
            continue;
        consonant++;
    }
    return consonant;
}
int main()
{

    char str[20];
     int consonant=0;
    cout<<"Enter the string ";
    gets(str);
    consonant=countc(str);
    cout<<"Number of consonant "<<consonant;
    return 0;
}

Method 4 : C++ program to find number of consonants in given string using recursion

#include<iostream>
#include<stdio.h>
using namespace std;
int countc(char *str,int consonant,int i)
{
    if(str[i]==0)
      return consonant;
    if(str[i]>'z'||str[i]<'A'||(str[i]>'Z'&&str[i]<'a'));
    else if(str[i]=='a'||str[i]=='e'||str[i]=='i'||str[i]=='o'||str[i]=='u'
         ||str[i]=='A'||str[i]=='E'||str[i]=='I'||str[i]=='O'||str[i]=='U');
    else
        consonant++;
    countc(str,consonant,i+1);
}
int main()
{

    char str[20];
    int consonant=0;
    cout<<"Enter the string ";
    gets(str);
    consonant=countc(str,0,0);
    cout<<"Number of consonant "<<consonant;
    return 0;
}

Method 5 : C++ program to find number of consonants in given string

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{

    char str[20];
    int consonant=0;
    cout<<"Enter the string ";
    gets(str);
    for(int i=0;str[i]!='\0';i++)
    {
        if(str[i]>'z'||str[i]<'A'||(str[i]>'Z'&&str[i]<'a'))
            continue;
        if(str[i]<'a')
            str[i]+=32;
        if(str[i]=='a'||str[i]=='e'||str[i]=='i'||str[i]=='o'||str[i]=='u')
            continue;
        consonant++;
    }
    cout<<"Number of consonant "<<consonant;
    return 0;
}