How to find if a given key exists in a C++ std::map

Use map::find

if ( m.find("f") == m.end() ) {
  // not found
} else {
  // found
}

Related Posts:

  1. C++ Loop through Map
  2. How can I print out C++ map values?
  3. What is the easiest way to initialize a std::vector with hardcoded elements?
  4. I’m getting Key error in python
  5. How do I merge dictionaries together in Python?
  6. C++ Double Address Operator? (&&)
  7. Simple dictionary in C++
  8. How do I erase an element from std::vector<> by index?
  9. When is del useful in Python?
  10. Is it more efficient to copy a vector by reserving and copying, or by creating and swapping? [duplicate]
  11. What is C# equivalent of in C++?
  12. How do I reverse a C++ vector?
  13. A proper way to create a matrix in c++
  14. A proper way to create a matrix in c++
  15. Why does the C++ STL not provide any “tree” containers?
  16. How to iterate through a list of objects in C++?
  17. How to remove all the occurrences of a char in c++ string
  18. Angular map. What is it?
  19. push_back vs emplace_back
  20. Map like structure in C: use int and struct to determine a value
  21. Python – How to fix “ValueError: not enough values to unpack (expected 2, got 1)”
  22. Parsing a comma-delimited std::string
  23. How to ensure that a std::map is ordered?
  24. Dictionary text file
  25. What is the difference between set and hashset in C++ STL?
  26. How do I efficiently iterate over each entry in a Java Map?
  27. How to sort Map values by key in Java?
  28. push_back vs emplace_back
  29. What is the difference between the HashMap and Map objects in Java?
  30. Remove spaces from std::string in C++
  31. What is the difference between const_iterator and non-const iterator in the C++ STL?
  32. Remove spaces from std::string in C++
  33. How to check that an element is in a std::set?
  34. What’s the most efficient way to erase duplicates and sort a vector?
  35. Best way to extract a subvector from a vector?
  36. How to sum up elements of a C++ vector?
  37. Implementation of Vector in C++
  38. Appending a vector to a vector
  39. Determine if map contains a value for a key?
  40. Initializing a static std::map in C++
  41. C++ Erase vector element by value rather than by position?
  42. How can you print a variable name in python? [duplicate]
  43. How to get current time in milliseconds?
  44. Use the auto keyword in C++ STL
  45. std::string length() and size() member functions
  46. Python AttributeError: ‘dict’ object has no attribute ‘append’
  47. sorting in std::map where key is a std::string
  48. How to do std::string indexof in C++ that returns index of matching string?
  49. How exactly do lookup tables work and how to implement them?
  50. Why are there no hashtables in the C standard library?
  51. Why can’t I make a vector of references?
  52. C++ equivalent of StringBuffer/StringBuilder?
  53. Displaying contents of a vector container in C++
  54. Map vs Object in JavaScript
  55. List iterator not dereferencable?
  56. How to iterate (keys, values) in JavaScript?
  57. The Definitive C++ Book Guide and List
  58. rand() between 0 and 1
  59. how to implement Interfaces in C++?
  60. What is the proper declaration of main in C++?
  61. What exactly is nullptr?
  62. Python list of dictionaries search
  63. How to make a SIMPLE C++ Makefile
  64. Convert float to std::string in C++
  65. “items list” or “item list”
  66. When and why do I need to use cin.ignore() in C++?
  67. What does int & mean
  68. Evaluate a string with a switch in C++ [duplicate]
  69. What is the best way to iterate over a dictionary?
  70. identifier “string” undefined?
  71. What does LPCWSTR stand for and how should it be handled with?
  72. Creating 2D dictionary in Python
  73. A warning – comparison between signed and unsigned integer expressions
  74. C++ network programming
  75. new types may not be defined in a return type – C++
  76. Is the practice of returning a C++ reference variable evil?
  77. How to pretty print nested dictionaries?
  78. How to fix ‘std::logic_error’ what(): basic_string::_M_construct null not valid error?
  79. Eclipse C++ : “Program “g++” not found in PATH”
  80. Why is my HelloWorld function not declared in this scope?
  81. TypeError: string indices must be integers, not str // working with dict
  82. What is the difference between include_directories and target_include_directories in CMake?
  83. Undefined reference to constructor
  84. Collection was modified; enumeration operation may not execute
  85. expected constructor, destructor, or type conversion before ‘(’ token
  86. Passing as const and by reference – Worth it?
  87. expression did not evaluate to a constant- c++
  88. How to print a string in C++
  89. How to check if input is numeric in C++
  90. C++ Big Integer
  91. How do I create a random alpha-numeric string in C++?
  92. Learning to work with audio in C++
  93. System not declared in scope?
  94. What is predicate in C++?
  95. no debugging symbols found when using gdb
  96. C++ Array of pointers: delete or delete []?
  97. Negative RGB Values
  98. DEV C ++ Error: expected declaration before ‘}’ token
  99. “cannot be used as a function error”
  100. error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup

Leave a Comment