Tag Archives: Find

How to find a substring in C++

Say we have the following string:

std::string str = "The quick brown fox jumps over the lazy dog";

And we want to find "fox"

Here are three methods:

  1. Use std::string::find()
  2. Use boost::contains()
  3. Use pystring::find()

Method 1: Use std::string::find

bool found = str.find("fox") != str.npos;

This returns an iterator pointing at the beginning of the substring if found, or std::string::npos otherwise.

Method 2: Use boost::contains

#include <boost/algorithm/string/predicate.hpp>
found = boost::contains(str, "fox");

This has the advantage of returning a boolean.

Reference: Function contains

Method 3: Use pystring::find

#include <pystring.h>
found = pystring::find(str, "fox") != -1;

Reference: imageworks/pystring