C++ 数据类型

C++ 数据类型

正如 变量 章节中所解释的，C++ 中的变量必须是指定的数据类型:

实例

#include <iostream>
#include <string>
using namespace std;
int main () {
  // Creating variables
  int myNum = 5;               // Integer (whole number)
  float myFloatNum = 5.99;     // Floating point number
  double myDoubleNum = 9.98;   // Floating point number
  char myLetter = 'D';         // Character
  bool myBoolean = true;       // Boolean
  string myString = "Hello";   // String
  // Print variable values
  cout << "int: " << myNum << "\n";
  cout << "float: " << myFloatNum << "\n";
  cout << "double: " << myDoubleNum << "\n";
  cout << "char: " << myLetter << "\n";
  cout << "bool: " << myBoolean << "\n";
  cout << "string: " << myString << "\n";
  return 0;
}

基础数据类型

数据类型指定变量将存储的信息的大小和类型:

通过使用 sizeof() 运算符，可以获取类型或变量的大小（以字节为单位（计算机占用的 RAM）:

实例

#include <iostream>
using namespace std;
int main() {
  cout << "Size of char: " << sizeof(char) << " bytes\n";
  cout << "Size of bool: " << sizeof(bool) << " bytes\n";
  cout << "Size of int: " << sizeof(int) << " bytes\n";
  cout << "Size of float: " << sizeof(float) << " bytes\n";
  cout << "Size of double: " << sizeof(double) << " bytes\n";
  return 0;
}

在接下来的章节中，您将学习到有关各个数据类型的更多信息。