问题描述
在学校里，我曾教过 string :: at ，但是通过探索字符串库，我看到了 string :: operator [] ，这是我以前从未见过的。
I was taught string::at in school, but by exploring the string library I saw string::operator[], which I was never shown before.
我现在正在使用 operator [] 并没有t以来一直在使用，但是有什么区别？
这是一些示例代码：
I'm now using operator[] and haven't used at since, but what is the difference?Here is some sample code:
std::string foo = "my redundant string has some text";
std::cout << foo[5];
std::cout << foo.at(5);
在输出方面，它们基本相同，但是有一些我不知道的细微差别
They are essentially the same in terms of output, but are there some subtle differences I'm not aware of?
推荐答案
是的，有一个主要区别：使用对通过的索引进行范围检查，如果索引在在这种情况下只会带来未定义的行为。
Yes, there is one major difference: using .at() does a range check on index passed and throws an exception if it's over the end of the string while operator[] just brings undefined behavior in that situation.
这篇关于string :: at和string :: operator []有什么区别？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！