Difference between != and =! with an example(in C++)

This operation:

A!=B

determines if A is not equal to B. If they’re not equal, it evaluates to true. If they are equal, it evaluates to false. It’s just a boolean comparison operation.

This operation:

A=!B

is not a boolean comparison. It sets the value of A to the negated value of B. (When used in this context it also evaluates to the new value of A, but isn’t really a “comparison” in that regard.) So if B is true then this will set the value of A to false. It can be seen much more clearly as:

A = !B

The first operation only compares, it doesn’t modify anything. The second operation modifies A.

Related Posts:

  1. Pause Console in C++ program
  2. Why the switch statement cannot be applied on strings?
  3. ld: symbol(s) not found for architecture x86_64 error
  4. C++ string to double conversion
  5. How do I print out the contents of a vector?
  6. Passing an array by reference
  7. What does int argc, char *argv[] mean?
  8. Meaning of = delete after function declaration
  9. Using NULL in C++?
  10. c++ “Incomplete type not allowed” error accessing class reference information (Circular dependency with forward declaration)
  11. C++ Error: undefined reference to `main’
  12. 1.#QNAN error C++
  13. What is the array form of ‘delete’?
  14. Error: Expression must have integral or unscoped enum type
  15. Use new operator to initialise an array
  16. Remove secure warnings (_CRT_SECURE_NO_WARNINGS) from projects by default in Visual Studio
  17. Replace part of a string with another string
  18. Error with multiple definitions of function
  19. What are C++ functors and their uses?
  20. invalid conversion from ‘const char*’ to ‘char*’
  21. Check if a string is palindrome
  22. What is an ‘undeclared identifier’ error and how do I fix it?
  23. Initializing a two dimensional std::vector
  24. What does “<<" and ">>” mean in C++ for cout/cin?
  25. C ++ error: a expected initializer before [function name]
  26. invalid new-expression of abstract class type
  27. std::string to char*
  28. Difference between using Makefile and CMake to compile the code
  29. Exception Error c0000005 in VC++
  30. push_back vs emplace_back
  31. Returning multiple values from a C++ function
  32. Eclipse C++ : “Program “g++” not found in PATH”
  33. no default constructor exists for class
  34. Press Enter to Continue
  35. How to trim a std::string?
  36. Parsing a comma-delimited std::string
  37. Random number c++ in some range
  38. Convert a String In C++ To Upper Case
  39. Is std::stoi actually safe to use?
  40. Visual Studio 2015 doesn’t have cl.exe
  41. Right way to split an std::string into a vector
  42. How to resize array in C++?
  43. C++: std does not have member “string”
  44. Fatal error: ‘stdafx.h’ file not found
  45. How do I add the MinGW bin directory to my system path?
  46. What’s the syntax for declaring an array of function pointers without using a separate typedef?
  47. What is the difference between const_iterator and non-const iterator in the C++ STL?
  48. Sorting Linked List C++ with pointers
  49. Get Unix timestamp with C++
  50. Class prototyping
  51. How to dynamically allocate an array of pointers in C++?
  52. Error C1083: Cannot open include file: ‘stdafx.h’
  53. How do you handle a “cannot instantiate abstract class” error in C++?
  54. How to cast the size_t to double or int C++
  55. How to get Current Directory?
  56. “used without template parameters”
  57. Reading from .txt file into two dimensional array in c++
  58. C++ Error ‘nullptr was not declared in this scope’ in Eclipse IDE
  59. C++ Simple hangman game
  60. “The system cannot find the file specified” when running C++ program
  61. Remove First and Last Character C++
  62. C++ Convert string (or char*) to wstring (or wchar_t*)
  63. Program received signal SIGSEGV, Segmentation fault
  64. Integer to hex string in C++
  65. Comparison of C++ unit test frameworks
  66. Why is inherited member not allowed?
  67. Error: macro names must be identifiers using #ifdef 0
  68. Error: free(): invalid next size (fast):
  69. Error: free(): invalid next size (fast):
  70. Fastest way to Convert String to Binary?
  71. Reading data from file into an array
  72. LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++
  73. Trying to use int in getline
  74. c++ error c2015: too many characters in constant
  75. Splitting a C++ std::string using tokens, e.g. “;”
  76. stoi function gives error: std::invalid_argument at memory location 0x0035E8D8. c++
  77. Stack around the variable ‘ ‘ was corrupted
  78. The difference between cin.ignore and cin.sync
  79. casting int to char using C++ style casting
  80. How to print (using cout) a number in binary form?
  81. What is the job of autogen.sh when building a c++ package on Linux
  82. Using G++ to compile multiple .cpp and .h files
  83. LPCSTR, LPCTSTR and LPTSTR
  84. How to do std::string indexof in C++ that returns index of matching string?
  85. variable or field declared void
  86. Invalid conversion from ‘char’ to ‘const char *’
  87. How do I deal with “signed/unsigned mismatch” warnings (C4018)?
  88. Creating folders in C++
  89. Modulo operator with negative values [duplicate]
  90. Finding the type of an object in C++
  91. C++ Simple Dice roll – how to return multiple different random numbers [duplicate]
  92. How can I get a file’s size in C++?
  93. Why can’t I make a vector of references?
  94. What does “-Wall” in “g++ -Wall test.cpp -o test” do?
  95. C++ equivalent of StringBuffer/StringBuilder?
  96. heap corruption detected | C++
  97. Update g++ but still old version
  98. module unsafe for SAFESEH image C++
  99. Why are there two different getline() functions (if indeed there are)?
  100. no matching function to call for “getline”

Leave a Comment