Assert is commonly known as assert. I personally think it is more accurate to verify the features. Here is its usage.

#include <iostream>   #include <assert.h>     // #define _NDEBUG     #ifndef _NDEBUG       #define _DEBUG   #endif // _DEBUG     using namespace std;    bool TestValue(int a)  {      if ( a > 100 )          return false;      else          return true;  }  int main()  {      int x = 10;      #ifdef _DEBUG       assert( TestValue(x) );      #endif       cout << "Hello world!" << endl;        x = 20;      assert( TestValue(x) );      cout << "New Hello World!" << endl;        x = 120;      #ifdef _DEBUG       assert( TestValue(x) );      #endif       cout << "The last line output!!!" << endl;        return 0;  }  #include <iostream>#include <assert.h>// #define _NDEBUG#ifndef _NDEBUG    #define _DEBUG#endif // _DEBUGusing namespace std;bool TestValue(int a){    if ( a > 100 )        return false;    else        return true;}int main(){    int x = 10;    #ifdef _DEBUG    assert( TestValue(x) );    #endif    cout << "Hello world!" << endl;    x = 20;    assert( TestValue(x) );    cout << "New Hello World!" << endl;    x = 120;    #ifdef _DEBUG    assert( TestValue(x) );    #endif    cout << "The last line output!!!" << endl;    return 0;}

 

// The whole process is very simple, and the idea is clear. You don't need to make comments. You can understand everything after you copy it and run it again.