Accessing a string element

The standard string class offers two ways to access a single character from a string object. The first one is to use the overloaded subscript operator [ ] like in the following example:

 #include  using namespace std;void main(){  string s = "hello world";  char c = s[0];  //assign  'h' to c}

Another way is to use the at() member function:

 try{  string s = "hello world";  char c = s.at(0);  //assign  'h' to c; safer than [ ] but less efficient. }catch(bad_range& str_ex) { //when accessing an out of range element, at() throws a bad_range exception/*..*/ }

There are two differences between these access methods. The [ ] operator is efficient but unsafe since it does not perform range checking. Accessing an out of range member is possible and results in an undefined behavior. The at() member function, on the other hand, is less efficient but safer, since it performs range checks. In case of an attempt to access an out of range member, it throws an exception of type std::bad_range. Please note that exactly the same access rules apply to vector<> as well.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

Top 5 B2B SaaS Marketing Agencies for 2023

In recent years, the software-as-a-service (SaaS) sector has experienced exponential growth as more and more companies choose cloud-based solutions. Any SaaS company hoping to stay ahead of the curve in this quickly changing industry needs to invest in effective marketing. So selecting the best marketing agency can mean the difference

technology leadership

Why the World Needs More Technology Leadership

As a fact, technology has touched every single aspect of our lives. And there are some technology giants in today’s world which have been frequently opined to have a strong influence on recent overall technological influence. Moreover, those tech giants have popular technology leaders leading the companies toward achieving greatness.

iOS app development

The Future of iOS App Development: Trends to Watch

When it launched in 2008, the Apple App Store only had 500 apps available. By the first quarter of 2022, the store had about 2.18 million iOS-exclusive apps. Average monthly app releases for the platform reached 34,000 in the first half of 2022, indicating rapid growth in iOS app development.