Aspiring coders and programming experts, welcome to this exciting tutorial on the “C++ find” function. This often underutilized yet highly valuable tool allows developers to find elements in various types of containers such as arrays, lists, and vectors with ease. By the end of this tutorial, you’ll realize that ‘finding’ has never been so easy or powerful!
Table of contents
What is C++ Find?
The C++ find function is part of the algorithm library in C++. It is primarily used to find the first occurrence of a specified element in a container like an array, list, or vector, from a specified starting position.
What is C++ Find used for?
The find function can be a lifesaver when dealing with significant amount of data. By allowing swift and precise searching within containers, it can save programmers from writing lengthy and convoluted code. Its relevancy extends across a wide range of applications, from game development to AI programming, making it a versatile tool to master.
Why should I learn it?
Understanding the C++ find function is crucial for developers as it optimizes code implementation by simplifying the process of searching within containers
Also, C++ find is fundamental to mastering C++ as it unlocks the potential to handle more complex tasks, like searching patterns, sorting data, or even developing intricate game features.
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Basic Example of How to Use C++ Find
Let’s begin with a simple and easy example of the C++ find functionality. We will use the find function to search a character in a vector container.
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<char> myVector = {'a', 'b', 'c', 'd'};
auto result = find(myVector.begin(), myVector.end(), 'c');
if (result != myVector.end()){
std::cout << "Element found in myVector: " << *result << "\n";
} else {
std::cout << "Element not found in myVector\n";
}
return 0;
}Using C++ Find with Different Types of Containers
In addition to vectors, the C++ find function can be used with other types of containers, including lists and arrays.
#include <algorithm>
#include <list>
#include <iostream>
int main() {
std::list<int> myList = {4, 9, 0, 2};
auto result = find(myList.begin(), myList.end(), 9);
if (result != myList.end()){
std::cout << "Element found in myList: " << *result << "\n";
} else {
std::cout << "Element not found in myList\n";
}
return 0;
}Find with Custom Search Function
It’s also possible to couple the C++ find function with a custom search function to find elements meeting certain conditions for more complex searches.
#include <algorithm>
#include <vector>
#include <iostream>
bool isOdd(int i) { return i % 2 == 1; }
int main() {
std::vector<int> myVector = {2, 4, 1, 7, 8};
auto result = find_if(myVector.begin(), myVector.end(), isOdd);
if (result != myVector.end()){
std::cout << "First odd number in myVector: " << *result << "\n";
} else {
std::cout << "No odd numbers found in myVector\n";
}
return 0;
}Searching within a Defined Range with C++ Find
The use of iterators in the find function allows for finding elements within a specified range in a container, offering more control during searches.
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<int> myVector = {5, 9, 3, 1, 8};
auto result = find(myVector.begin() + 1, myVector.begin() + 3, 3);
if (result != myVector.end()){
std::cout << "Element found in the defined range: " << *result << "\n";
} else {
std::cout << "Element not found in the defined range\n";
}
return 0;
}Combining C++ Find with Other Functions
Standalone C++ find is already great, but combining it with other functions or objects can unlock an even greater potential. Combining find and vector.erase(), for example, enables finding and removing elements in a container. Let’s learn how.
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<int> myVector = {5, 9, 3, 1, 8};
auto result = find(myVector.begin(), myVector.end(), 3);
if (result != myVector.end()){
myVector.erase(result);
std::cout << "Element found and removed!" << "\n";
} else {
std::cout << "Element not found\n";
}
return 0;
}The Power of C++ Find_if
C++ Find also comes with a variant named find_if, which is highly adaptable and allows you to define your own criteria for finding elements. By providing a function or a lambda expression for the condition, you can customize the search to your exact requirements. Let’s look at an example.
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<int> myVector = {7, 14, 21, 29, 41, 56, 68};
auto multipleOfSeven = [](int i) { return i % 7 == 0; };
auto result = find_if(myVector.begin(), myVector.end(), multipleOfSeven);
if (result != myVector.end()){
std::cout << "First multiple of seven found: " << *result << "\n";
} else {
std::cout << "No multiples of seven found\n";
}
return 0;
}Locating All Instances of an Element
Not just the first, the C++ find can also locate all instances of an element in a container. By creating a loop that continues to search the remainder of the container after every find, we can get locations of all instances. Here’s how:
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<int> myVector = {8, 9, 3, 8, 1, 8};
std::vector<int>::iterator result = myVector.begin();
while((result = find(result, myVector.end(), 8)) != myVector.end()){
std::cout << "Found 8 at position: " << distance(myVector.begin(), result) << "\n";
result++;
}
return 0;
}Finding the First Mismatch with C++
Looking to identify the first dissimilarity between two containers? Utilize the mismatch function in C++. This function compares two containers and returns a pair of iterators pointing to the first non-matching elements. Here’s an example:
#include <algorithm>
#include <vector>
#include <iostream>
int main() {
std::vector<int> myVector1 = {1, 2, 3, 4};
std::vector<int> myVector2 = {1, 2, 6, 4};
auto result = mismatch(myVector1.begin(), myVector1.end(), myVector2.begin());
std::cout << "First mismatch found at position: " << distance(myVector1.begin(), result.first) << "\n";
return 0;
}Now equipped with these powerful search techniques, you can handle large containers with ease and precision. It might not be long before you start finding uses for them in your own projects. Happy coding!
Working with C++ Find on Strings
Digging deeper into the utility of the C++ find function, it is also possible to apply this powerful tool in exploring and searching within strings. Let’s look at how we can apply find functions to strings:
#include <iostream>
#include <string>
int main() {
std::string myString = "Zenva Academy";
size_t found = myString.find("Academy");
if (found!=std::string::npos) {
std::cout << "'Academy' found at position: " << found << '\n';
}
return 0;
}Finding Multiple Instances in a String
Here’s how you can find multiple instances of a substring within a given string:
#include <string>
#include <iostream>
int main() {
std::string myString = "The quick brown fox jumps over the lazy dog";
size_t pos = myString.find("the");
while (pos != std::string::npos) {
std::cout << "Found 'the' at position: " << pos << '\n';
pos = myString.find("the", pos + 1);
}
return 0;
}Using Find_First_of and Find_Last_of Functions
Up for finding the first or the last of any character of a specific set in a string? C++ has got you covered! The find_first_of and find_last_of functions allow you to do just that, adding more versatility to your toolbox:
#include <string>
#include <iostream>
int main() {
std::string myString = "abcABCabcABCabc";
size_t found_first = myString.find_first_of("ABC");
size_t found_last = myString.find_last_of("ABC");
std::cout << "First uppercase letter found at position: " << found_first << '\n';
std::cout << "Last uppercase letter found at position: " << found_last << '\n';
return 0;
}The Power of Find_first_not_of and Find_last_not_of
Adding to the list, let’s move to the find_first_not_of and find_last_not_of functions. These allow you to find the first or the last characters that are NOT in the defined character set, coming handy when you are working with exclusion sets:
#include <string>
#include <iostream>
int main() {
std::string myString = "122333444455555";
size_t found_first = myString.find_first_not_of("12");
size_t found_last = myString.find_last_not_of("5");
std::cout << "First number different from 1 and 2 found at position: " << found_first << '\n';
std::cout << "Last number different from 5 found at position: " << found_last << '\n';
return 0;
}By now, you have delved into the depths of the C++ find function and discovered its diverse and expansive possibilities. Regardless of the task at hand – whether trivial or tiresome, C++ find is a potent ally for all C++ programmers. It indeed makes the job of finding elements or patterns in containers a bit more efficient and a lot less complicated. So keep practicing, keep exploring, and most importantly, keep finding with C++ find!
Where to Go Next?
With the C++ ‘find’ feature now in your programming arsenal, your journey is far from over. In this expansive field, every step you take opens new doors of opportunities and challenges.
Most importantly, remember that learning coding or any other skill gets easier and more interesting when you’re exposed to practical, engaging and insightful materials. We, at Zenva, aim to offer exactly that kind of learning experience.
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Conclusion
Cracking the code of ‘finding’ with the C++ find function is just scratching the surface of your coding journey. The realm of programming is vast and varied, and every new command or function you learn opens doors for more advanced and exciting endeavors.
At Zenva, we are here to guide you every step of the way, ensuring your learning is stress-free and packed with real-world relevance. Explore our C++ Programming Bundle to dive deeper into the world of coding. Your journey to becoming a coding expert is just a few clicks away!
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