OK some answers about malloc were already posted. The more interesting part is how free works (and in this direction, malloc too can be understood better). In many malloc/free implementations, free does normally not return the memory to the operating system (or at least only in rare cases). The reason is that you will get gaps in … Read more
According to the C++ Standard 1 The && operator groups left-to-right. The operands are both contextually converted to bool (Clause 4). The result is true if both operands are true and false otherwise. Unlike &, && guarantees left-to-right evaluation: the second operand is not evaluated if the first operand is false. and 1 The || operator groups left-to-right. … Read more
In C++11, use std::stoi as: std::string s = “10”; int i = std::stoi(s); Note that std::stoi will throw exception of type std::invalid_argument if the conversion cannot be performed, or std::out_of_range if the conversion results in overflow(i.e when the string value is too big for int type). You can use std::stol or std:stoll though in case int seems too small for the input string. In C++03/98, any of the following can be … Read more
To understand this you’ll first need to understand pointers and references. I’ll simply explain the type declaration syntax you’re asking about assuming you already know what pointers and references are. In C, it is said that ‘declaration follows use.’ That means the syntax for declaring a variable mimics using the variable: generally in a declaration … Read more
std::string doesn’t contain such function but you could use stand-alone replace function from algorithm header.
I’ve never heard of a best practice for this specific question. However, one best practice in general is to use the simplest solution that solves the problem. In this case the array-style access (or c-style if you want to call it that) is the simplest way to iterate while having the index value available. So … Read more
Declare the parameterless constructor in the header file: You are defining it in the .cpp file without actually declaring it. But since the compiler provides such a constructor by default (if no other constructor is declared), the error clearly states that you are trying to define an implicitly-declared constructor.
ios::out opens the file for writing. ios::binary makes sure the data is read or written without translating new line characters to and from \r\n on the fly. In other words, exactly what you give the stream is exactly what’s written.
You get this error when you don’t have a file (Checker.cpp) here to make. Its probably for the following reasons : Your current directory is not the directory in which your file resides. The file may have been moved to somewhere else. Or the worse , the file doesn’t exist.