c++ oop cheat sheet code example
Example 1: C++ CHEAT SHEAT
#include <future> // Include future
function<int(int)> fib = // Create lambda function
[&](int i){
if (i <= 1){
return 1;
}
return fib(i-1)
+ fib(i-2);
};
future<int> fut = // result of async function
async(launch::async, fib, 4); // start async function in other thread
// do some other work
cout << fut.get(); // get result of async function. Wait if needed.
Example 2: c++ cheat sheet
255, 0377, 0xff // Integers (decimal, octal, hex)
2147483647L, 0x7fffffffl // Long (32-bit) integers
123.0, 1.23e2 // double (real) numbers
'a', '\141', '\x61' // Character (literal, octal, hex)
'\n', '\\', '\'', '\"' // Newline, backslash, single quote, double quote
"string\n" // Array of characters ending with newline and \0
"hello" "world" // Concatenated strings
true, false // bool constants 1 and 0
nullptr // Pointer type with the address of 0
Example 3: c++ cheat sheet
x=y; // Every expression is a statement
int x; // Declarations are statements
; // Empty statement
{ // A block is a single statement
int x; // Scope of x is from declaration to end of block
}
if (x) a; // If x is true (not 0), evaluate a
else if (y) b; // If not x and y (optional, may be repeated)
else c; // If not x and not y (optional)
while (x) a; // Repeat 0 or more times while x is true
for (x; y; z) a; // Equivalent to: x; while(y) {a; z;}
for (x : y) a; // Range-based for loop e.g.
// for (auto& x in someList) x.y();
do a; while (x); // Equivalent to: a; while(x) a;
switch (x) { // x must be int
case X1: a; // If x == X1 (must be a const), jump here
case X2: b; // Else if x == X2, jump here
default: c; // Else jump here (optional)
}
break; // Jump out of while, do, or for loop, or switch
continue; // Jump to bottom of while, do, or for loop
return x; // Return x from function to caller
try { a; }
catch (T t) { b; } // If a throws a T, then jump here
catch (...) { c; } // If a throws something else, jump here