Go – Does a break statement break from a switch/select

breakgoselectswitch statement

I know that switch/select statements break automatically after every case. I am wondering, in the following code:

for {
    switch sometest() {
    case 0:
        dosomething()
    case 1:
        break
    default:
        dosomethingelse()
    }
}

Does the break statement exit the for loop or just the switch block?

Best Answer

Break statements, The Go Programming Language Specification.

A "break" statement terminates execution of the innermost "for", "switch" or "select" statement.
BreakStmt = "break" [ Label ] .
If there is a label, it must be that of an enclosing "for", "switch" or "select" statement, and that is the one whose execution terminates (§For statements, §Switch statements, §Select statements).
L:
  for i < n {
      switch i {
      case 5:
          break L
      }
  }

Therefore, the break statement in your example terminates the switch statement, the "innermost" statement.

Related Solutions

Python – Replacements for switch statement in Python

The original answer below was written in 2008. Since then, Python 3.10 (2021) introduced the match-case statement which provides a first-class implementation of a "switch" for Python. For example:

def f(x):
    match x:
        case 'a':
            return 1
        case 'b':
            return 2
        case _:        
            return 0   # 0 is the default case if x is not found

The match-case statement is considerably more powerful than this simple example.

You could use a dictionary:

def f(x):
    return {
        'a': 1,
        'b': 2,
    }[x]

C# – Multiple cases in switch statement

I guess this has been already answered. However, I think that you can still mix both options in a syntactically better way by doing:

switch (value)
{
    case 1: case 2: case 3:          
        // Do Something
        break;
    case 4: case 5: case 6: 
        // Do Something
        break;
    default:
        // Do Something
        break;
}

Best Answer

Related Solutions

Python – Replacements for switch statement in Python

C# – Multiple cases in switch statement

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