C++ Programming Tricks You Should Know Master some of the crucial C++ concepts and save a few lines

  1. Include All Standard Libraries in One Go

For example, you can replace this (and many more):

With this:

#include <bits/stdc++.h>

  1. Use Auto To Omit the Data Type of a Variable

As an example, the data types of the following variables are declared during runtime.

auto a = ‘a’;
auto t = true;
auto x = 1;
auto y = 2.0;

  1. Comprehensive Range-Based for Loops

The syntax of a range-based for loop is:
for(range_declaration : range_expression)
As an example, you can loop through an array of numbers using a range-based for-loop as follows:

int numbers[] = {1,2,3,4,5};
for (auto number: numbers){
cout << number << endl;

  1. One Liner If…Else Statements

As an example, you can replace this expression:
int age = 9;

if(age < 18) {
printf(“A Child”);
} else {
printf(“An Adult”);

With a lot neater shorthand, like this:

age < 18 ? printf(“A Child”) : printf(“An Adult”);

  1. Swap Two Variables Without the Third

You can use the XOR operator to swap two variables without using a third helper variable. Here’s an example:
int a = 1;
int b = 2;

a ^= b ^= a ^= b;

  1. The → Operator

You can use the → “operator” in a while loop as a “Goes to” operator.
For example, you can print numbers 9 8 7 6 5 4 3 2 1 with a while loop like this:

int x = 10;
while( x → 0 ) {
printf("%d ", x);

Note: → is actually not an operator, but rather a combination of two operators, – and >.
The above while is the same as while( (x–) > 0 ), which reads “decrement x by 1 and then compare the result with 0.”

  1. Pre-Increment Is Faster Than Post-Increment

In C++, there are two operators that can be used to increment a value by 1:
Pre-increment, ++i — Before assigning the value to the variable, the value is incremented by one.
Post-increment, i++ — After assigning the value to the variable, the value is incremented.

As a result, pre-increment, ++i, is faster than post-increment because post-increment keeps a copy of the previous value whereas pre-increment directly adds 1 without copying the last value.

  1. Combine Assignment With a Function Call
    In C++, you can combine an assignment and a function call.
    Instead of this:
    int i;
    i = 10;
    printf("%d", i); // prints 10
    You can do this to save some code lines:
    int i;
    printf("%d", i = 10); // prints 10

That’s it!
Thanks for reading! I hope you find it useful.

#programming #dsa #cp #codechef #c++ #beginners


Point 7. Pre-increment/Pre-decrement is not related to C++ programming language only. It should apply also to any other programming language that has the same operational semantics of these unary operators, such as Java.

Best wishes