How can I check if given int exists in array? [duplicate]

Question

For example, I have this array:

int myArray[] = { 3, 6, 8, 33 }; 

How to check if given variable x is in it?

Do I have to write my own function and loop the array, or is there in modern c++ equivalent to in_array in PHP?

Answer 1

You can use std::find for this:

#include <algorithm> // for std::find #include <iterator> // for std::begin, std::end  int main ()  {   int a[] = {3, 6, 8, 33};   int x = 8;   bool exists = std::find(std::begin(a), std::end(a), x) != std::end(a); } 

std::find returns an iterator to the first occurrence of x, or an iterator to one-past the end of the range if x is not found.

Answer 2

I think you are looking for std::any_of, which will return a true/false answer to detect if an element is in a container (array, vector, deque, etc.)

int val = SOME_VALUE; // this is the value you are searching for bool exists = std::any_of(std::begin(myArray), std::end(myArray), [&](int i) {     return i == val; }); 

If you want to know where the element is, std::find will return an iterator to the first element matching whatever criteria you provide (or a predicate you give it).

int val = SOME_VALUE; int* pVal = std::find(std::begin(myArray), std::end(myArray), val); if (pVal == std::end(myArray)) {     // not found } else {     // found }