break statement

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

C++ language

General topics
Preprocessor Comments	Keywords Escape sequences
Flow control
Conditional execution statements
if	switch
Iteration statements (loops)
for range-for (C++11)	while do-while
Jump statements
continue - break	goto - return
Functions
Function declaration
Lambda function expression
inline specifier
Dynamic exception specifications (until C++17*)
noexcept specifier (C++11)
Exceptions
throw-expression try block	handler
Namespaces
Namespace declaration	Namespace aliases
Types
Fundamental types Enumeration types Function types	Class/struct types Union types
Specifiers
const/volatile decltype (C++11) auto (C++11)	constexpr (C++11) consteval (C++20) constinit (C++20)
Storage duration specifiers
Initialization
Default-initialization Value-initialization Zero-initialization Copy-initialization Direct-initialization	Aggregate initialization List-initialization (C++11)   Constant initialization Reference initialization

Expressions
Value categories Order of evaluation	Operators Operator precedence
Alternative representations
Literals
Boolean - Integer - Floating-point
Character - String - nullptr (C++11)
User-defined (C++11)
Utilities
Attributes (C++11)
Types
typedef declaration
Type alias declaration (C++11)
Casts
Implicit conversions static_cast const_cast	Explicit conversions dynamic_cast reinterpret_cast
Memory allocation
new expression	delete expression
Classes
Class declaration Constructors this pointer	Access specifiers friend specifier
Class-specific function properties
Virtual function override specifier (C++11)   final specifier (C++11)	explicit (C++11) static
Special member functions
Default constructor Copy constructor Move constructor (C++11)	Copy assignment Move assignment (C++11) Destructor
Templates
Class template Function template	Template specialization Parameter packs (C++11)
Miscellaneous
Inline assembly	History of C++

 

Statements

Labels

label : statement

Expression statements

expression ;

Compound statements

{ statement... }

Selection statements

if

switch

Iteration statements

while

do while

for

range for (C++11)

Jump statements

break

continue

return

goto

Declaration statements

declaration ;

Try blocks

try block

Transactional memory

synchronized, atomic_commit, etc (TM TS)

 

Causes the enclosing for, range-for, while or do-while loop or switch statement to terminate.

Used when it is otherwise awkward to terminate the loop using the condition expression and conditional statements.

Syntax

attr (optional) break ;

attr

-

(since C++11) any number of attributes

Explanation

Appears only within the statement of a loop body (while, do-while, for) or within the statement of a switch. After this statement the control is transferred to the statement immediately following the enclosing loop or switch. As with any block exit, all automatic storage objects declared in enclosing compound statement or in the condition of a loop/switch are destroyed, in reverse order of construction, before the execution of the first line following the enclosing loop.

Notes

A break statement cannot be used to break out of multiple nested loops. The goto statement may be used for this purpose.

Keywords

break

Example

Run this code

#include <iostream>
 
int main()
{
    int i = 2;
    switch (i)
    {
        case 1: std::cout << "1";   // <---- maybe warning: fall through
        case 2: std::cout << "2";   // execution starts at this case label (+warning)
        case 3: std::cout << "3";   // <---- maybe warning: fall through
        case 4:                     // <---- maybe warning: fall through
        case 5: std::cout << "45";  //
                break;              // execution of subsequent statements is terminated
        case 6: std::cout << "6";
    }
    std::cout << '\n';
 
    for (char c = 'a'; c < 'c'; c++)
    {
        for (int i = 0; i < 5; i++)      // only this loop is affected by break
        {                                //
            if (i == 2)                  //
                break;                   //
            std::cout << c << i << ' ';  //
        }
    }
    std::cout << '\n';
}

Possible output:

2345
a0 a1 b0 b1

See also

[[fallthrough]](C++17)	indicates that the fall through from the previous case label is intentional and should not be diagnosed by a compiler that warns on fall-through (attribute specifier)
C documentation for break