查找字符串的第一个字符，然后将其与符号c ++进行比较 [英] Find first character of string, then compare it with a symbol c++

问题描述

尝试检查字符串的第一个字符以查看其是否包含"/".

Attempting to check the first character of a string to see if it contains a "/".

string pathname = "/test";
if(pathname.at(0) == "/")
{
    // if first character is a slash then delete the slash
    // but only delete the slash if it's the first character
    pathname.erase(pathname.begin()+0);
}

我知道上面的代码将无效，因为pathname.at(0)被认为是一个整数.

I understand that the above code will not work because pathname.at(0) is considered an int.

我确定这已经被问过了.但是我环顾了很多.我已经看到了substr方法，find方法和许多其他方法.我似乎无法使他们正常工作.

I'm sure this has been asked before. But I have looked around a lot. I've seen the substr method the find method and many others. I can't seem to get them working right though.

建议?预先感谢.

推荐答案

对字符常量使用单引号.

if(pathname.at(0) == '/')
                     ^ ^

无论内部有多少个字符，双引号都表示一个 C风格的字符串.您无法将字符与C字符串进行比较.

Double quotes, no matter how many characters are inside, represents a C-style string. You can't compare a character to a C-string.

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