Menu
×
NEW W3Schools app iOS & Android Start the adventure Spaces Upgrade Paid Courses Spaces Upgrade Paid Courses
   ❮     
HTML CSS JAVASCRIPT SQL PYTHON JAVA PHP C C++ C# AWS W3.CSS HOW TO BOOTSTRAP REACT MYSQL JQUERY EXCEL XML DJANGO NUMPY PANDAS NODEJS DSA TYPESCRIPT ANGULAR ANGULARJS GIT POSTGRESQL MONGODB ASP AI R GO KOTLIN SWIFT SASS VUE GEN AI SCIPY CYBERSECURITY DATA SCIENCE INTRO TO PROGRAMMING INTRO TO HTML & CSS BASH RUST TOOLS

C++ Tutorial

C++ HOME C++ Intro C++ Get Started C++ Syntax
Syntax Statements Code Challenge
C++ Output
Print Text Print Numbers New Lines Code Challenge
C++ Comments C++ Variables
Declare Variables Multiple Variables Identifiers Constants Real-Life Examples Code Challenge
C++ User Input C++ Data Types
Basic Data Types Numbers Decimal Precision Booleans Characters Strings The auto Keyword Real-Life Example Code Challenge
C++ Operators
Operators Arithmetic Assignment Comparison Logical Precedence Code Challenge
C++ Type Conversion C++ Strings
Strings Intro Concatenation Numbers and Strings String Length Access Strings Special Characters User Input Strings Omitting Namespace C-Style Strings Convert Strings Code Challenge
C++ Math C++ Booleans
Boolean Values Boolean Expressions Real-Life Example Code Challenge
C++ If...Else
if else else if Short hand if..else Nested if Logical Operators Real-Life Examples Code Challenge
C++ Switch
Switch Code Challenge
C++ While Loop
While Loop Do/While Loop Real-Life Examples Code Challenge
C++ For Loop
For Loop Nested Loops The foreach Loop Real-Life Examples Code Challenge
C++ Break/Continue C++ Arrays
Arrays Arrays and Loops Omit Array Size Get Array Size Real-Life Example Multidimensional Arrays Code Challenge
C++ Structures C++ Enums C++ References
Create References Memory Address
C++ Pointers
Create Pointers Dereferencing Modify Pointers
C++ Memory Mgmt
Memory Management new and delete Smart Pointers

C++ Functions

C++ Functions C++ Function Parameters
Parameters/Arguments Default Parameter Multiple Parameters Return Values Pass By Reference Pass Arrays Pass Structures Real-Life Example
C++ Function Overloading C++ Scope C++ Recursion C++ Lambda

C++ Classes

C++ OOP C++ Classes/Objects C++ Class Methods C++ Constructors
Constructors Constructor Overloading
C++ Destructors C++ The this Pointer C++ Access Specifiers C++ Encapsulation C++ Friend Functions C++ Inheritance
Inheritance Multilevel Inheritance Multiple Inheritance Access Specifiers
C++ Polymorphism
Polymorphism Virtual Functions Abstract Classes
C++ Operator Overload C++ Templates

C++ Files

C++ Files

C++ Date

C++ Date

C++ Errors

C++ Errors C++ Debugging C++ Exceptions C++ Input Validation

C++ Problem Solving

C++ Problem Solving C++ Build the Logic C++ Test Cases

C++ Data Structures

C++ Data Structures & STL C++ Vectors C++ List C++ Stacks C++ Queues C++ Deque C++ Sets C++ Maps C++ Unordered Map C++ Unordered Set C++ Iterators C++ Algorithms

C++ Namespaces

C++ Namespaces

C++ Projects

C++ Projects

C++ Cert

C++ Certificate

C++ How To

C++ How Tos
How Tos Add Two Numbers Swap Two Variables Even or Odd Number Reverse a Number Positive or Negative Square Root Area of Rectangle Celsius to Fahrenheit Sum of Digits Armstrong Number Random Number Count Words Count Vowels in a String Remove Vowels Count Digits in a String Reverse a String Palindrome Check Check Anagram Split a String Remove Whitespace Count Character Frequency Sum of Array Elements Find Array Average Sort an Array Find Smallest Element Find Largest Element Second Largest Array Min and Max in Array Merge Two Arrays Remove Duplicates Find Duplicates Shuffle an Array Factorial of a Number Fibonacci Sequence Find GCD Check Prime Number Loop Through a Vector Loop Through a Map

C++ Examples

C++ Examples C++ Real-Life Examples C++ Compiler C++ Exercises C++ Quiz C++ Code Challenges C++ Practice Problems C++ Syllabus C++ Study Plan

C++ Reference

C++ Reference C++ Keywords C++ <algorithm> C++ <cctype> C++ <cmath> C++ <cstdlib> C++ <cstring> C++ <ctime> C++ <deque> C++ <fstream> C++ <iomanip> C++ <iostream> C++ <list> C++ <map> C++ <memory> C++ <queue> C++ <random> C++ <set> C++ <sstream> C++ <stack> C++ <stdexcept> C++ <string> C++ <unordered_map> C++ <unordered_set> C++ <vector>


C++ queue size() Function

❮ queue Functions

Example

Get the number of elements in a queue:

queue<string> cars;
cars.push("Volvo");
cars.push("BMW");
cars.push("Ford");
cars.push("Mazda");
cout << cars.size();

Try it Yourself »

Share

Definition and Usage

The size() function returns the number of elements in a queue.

The size function is defined in the <queue> header file.

Syntax

queue.size();

Parameter Values

None.

Technical Details

Returns: The number of elements in the queue (a non-negative integer).

Related Pages

Read more about queues in our Queues Tutorial.

❮ queue Functions

This way to the W3Schools Adventure app
Learn more about Adventure Mode›

Free account

Track your progress

XP earned 0 Day streak 0 Spaces 0 League —

New

Learn in Adventure Mode W3Schools Adventure App

Coding fundamentals as bite-sized lessons and challenges.

Download on the App Store GET IT ON Google Play TRY NOW IN Browser
PLUS
SPACES
GET CERTIFIED
FOR TEACHERS
PRACTICE
CONTACT US
×

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail:
help@w3schools.com

Top Tutorials
HTML Tutorial
CSS Tutorial
JavaScript Tutorial
How To Tutorial
SQL Tutorial
Python Tutorial
W3.CSS Tutorial
Bootstrap Tutorial
PHP Tutorial
Java Tutorial
C++ Tutorial
jQuery Tutorial
Top References
HTML Reference
CSS Reference
JavaScript Reference
SQL Reference
Python Reference
W3.CSS Reference
Bootstrap Reference
PHP Reference
HTML Colors
Java Reference
AngularJS Reference
jQuery Reference
Top Examples
HTML Examples
CSS Examples
JavaScript Examples
How To Examples
SQL Examples
Python Examples
W3.CSS Examples
Bootstrap Examples
PHP Examples
Java Examples
XML Examples
jQuery Examples
Get Certified
 HTML Certificate
CSS Certificate
JavaScript Certificate
Front End Certificate
SQL Certificate
Python Certificate
PHP Certificate
jQuery Certificate
Java Certificate
C++ Certificate
C# Certificate
XML Certificate
FORUM ABOUT CAMPUS
W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning.
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness
of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookies and privacy policy.

Copyright 1999-2026 by Refsnes Data. All Rights Reserved. W3Schools is Powered by W3.CSS.