i wanted to create a function where i can enter a string and it would output a a jumbled version of the string

i cant seem to figure out what wrong

for some reason it wont compile and it think theres a problem on my jumbleString function

#include <iostream>
#include <iomanip>
#include <string>
#include <istream>

using namespace std;

int main ()
{
    int lengthofstring, x, countWords(string str), countConsonant(string str, int), consonant, jumbleString(string str);
    string str, str2, wordone;

    char options;
    cout << "Please enter a word, a sentence, or a string of numbers." << endl;

    getline(cin, str);

    //cin >> str;

    lengthofstring = str.length(); 
    str2=str;

    bool another= true;

    while (another) 
    {
        cout << '\n' << "USE THIS MENU TO MANIPULATE YOUR STRING" << endl;
        cout << "---------------------------------------" << endl;
        cout << "1) Inverse String" << endl;
        cout << "2) Reverse String" << endl;
        cout << "3) To Uppercase" << endl;
        cout << "4) Jum开发者_如何学编程ble String" << endl;
        cout << "5) Count Number Words" << endl;
        cout << "6) Count Consonants" << endl;
        cout << "7) Enter a Different String" << endl;
        cout << "8) Print the String" << endl;
        cout << "Q) Quit" << endl;

        cin >> options;

        switch (options)
        {
        case '1':
            for (x = 0; x < lengthofstring; x++)
            {
                if (islower(str[x]))
                    str[x] = toupper(str[x]);
                else if (isupper(str[x]))
                    str[x] = tolower(str[x]);

            }
            cout<< str;
            break;
        case '2':
            for (x = 0; x < lengthofstring; x++)
            {
                str2[x] = str[lengthofstring-1-x];
            }
            cout<< str2;
            break;
        case '3':
            {
                for (x = 0; x < lengthofstring; x++)
                { 
                    if (islower(str[x]))
                        str[x] = toupper(str[x]);
                }
                cout<< str;
            }
            break;
        case '4':
            jumbleString(str);
            break;

        case '5':
            cout << countWords(str);
            break;
        case '6': 
            consonant = 0;
            cout<< countConsonant(str, consonant);
            break;
        case '7':
            cout << "Please enter another word, a sentence, or a string of numbers." << endl;
            cin.ignore();
            getline(cin, str);
            cout << str <<endl;
            break;
        case '8':
            cout<< str2;
            break;
        case 'q':
            another = false;
            break;
        }
    }

    cin.get();
    cin.get();
    return 0;
}

void jumbleString(string str)
{
    int length = str.length();
    int  j, k;

    for(int i = 0; i < length; j++)
    {
        k = rand() % length;
        j = rand() % length;
        char c = str[j];
        str[j] = str[k];
        str[k] = c;
    }

    cout << str<<endl;
}

int countWords(string str)
{
    int length = str.length();
    int words = 1;
    for(int size = 1; length > size; size++)
    {
        if (str[size] == ' ' && str[size-1] != ' ')
            words++;
    }
    if (str[0] == ' ')
        words--;
    return words;
}
int countConsonant(string str, int consonant)
{
    int length = str.length();
    consonant = 0;

    for (int i = 0; i < length; i++)
    {
        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' && str[i] != ' '&& str[i] != '1'
            && str[i] != '2' && str[i] != '3' && str[i] != '4' && str[i] != '5' && str[i] != '6'
            && str[i] != '7' && str[i] != '8' && str[i] != '9' && str[i] != '0')
            consonant = consonant + 1;
    }
    return consonant;
}

the problem is changing i inside the loop (I guess you meant to change k):
if you did mean to set k, change i = rand() % length; into k = rand() % length;
also, your question is a variant of the permutation problem, which Fisher-Yates solves. I would suggest looking at it, you will probably get better "randomness" by using it.

You are mistakenly using the loop variable, i , twice here. Also you might want to seed the random number generator if you want truly random jumbling of the strings.

For an idiomatic way of doing this in c++ you can use the standard algorithms to do this as follows:

#include <iostream>
#include <algorithm>
#include <ctime>
#include <cstdlib>

int main(void){
        srand ( unsigned ( time (NULL) ) );//seed the random shuffle

        std::string test = "abcdef";
        std::cout << "original string: " << test << std::endl;
        std::random_shuffle(test.begin(),test.end());
        std::cout << "shuffled string: " << test << std::endl;
        return 0;
}

You are using i, j for your two random indices whereas these should be j, k.

It should be:

j = rand() % length;
k = rand() % length;

You are using i as loop variable but at the same time assign a random value to it within the loop.

A possible solution would be not to use two randoms at all but instead the iterating variable i itself [online example].

for(int i = 0; i < length; i++)
{
    j = i + (rand() % (length-i));
    char c = str[j];
    str[j] = str[i];
    str[i] = c;
}