CODEWITHSUNDEEP
c++arraysloopsfor-loop
Mauri
Mauri

Reputation: 53

check if value exists in all indexes of array

So i have an array (size 5) of characters, each index containing a character, and i'm getting user input of a character to search for in the array. But i'm not sure how to check if char cInput is present in all indexes of the array.

char cLetters[5] = {'b', 'b', 'b', 'b', 'b'};
char cInput;
cout << "Enter a character to search for: ";
cin >> cInput;

I shouldn't have to do this right?

if(cInput == cLetters[0] && cInput == cLetters[1] && cInput == cLetters[2] 
&& cInput == cLetters[3] && cInput == cLetters[4])
          return true;

Especially if the size of the array was 200, i wouldn't write that condition 200 times.

Any ideas?

Upvotes: 3

Views: 1830

Answers (4)

sekmet64
sekmet64

Reputation: 1665

I'm looking for a way to do this with bools and came up with this:

auto is_true = std::bind(std::equal_to<bool>(), std::placeholders::_1, true);
return std::all_of(v.begin(), v.end(), is_true)

With a const char it would look like so:

auto is_b = std::bind(std::equal_to<char>(), std::placeholders::_1, 'b');
return std::all_of(v.begin(), v.end(), is_b)

Upvotes: 2

Jerry Coffin
Jerry Coffin

Reputation: 490088

Another possibility would be to use a C++11 range-based for loop to simplify the code a little:

for (auto ch : cLetters)
    if (ch != cInput)
        return false;
return true;

Upvotes: 0

pravish
pravish

Reputation: 33

The input char is not present in all indices if it is absent in either one of those. Loop through the array to see that

for (int i=0; i<5; ++i){
    if (cInput != cLetters[i])
        return 0;
}
return 1;

Upvotes: 0

Rapptz
Rapptz

Reputation: 21317

Use the C++11 algorithm in <algorithm>, std::all_of.

Example code:

#include <algorithm>
#include <iostream>

int main() {
    char x[] = { 'b', 'b', 'b', 'b', 'b' };
    if(std::all_of(std::begin(x), std::end(x), [](char c) { return c == 'b'; })) {
        std::cout << "all are b!";
    }
}

Upvotes: 10

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