Attention

IronPLC implements many parts of the IEC 61131-3 standard and is working toward full Structured Text support. Key features still missing include arrays and structures. Try it out in the IronPLC Playground.

CASE

The CASE statement selects one of several statement groups based on the value of an integer expression.

IEC 61131-3	Section 3.3.2.3
Support	Supported

Syntax

CASE expression OF
    case_value { ',' case_value } ':' statement_list
    { case_value { ',' case_value } ':' statement_list }
[ ELSE
    statement_list ]
END_CASE ;

Each case_value is an integer literal or a subrange (low .. high). Multiple values can be listed separated by commas.

Description

The CASE statement evaluates the expression and compares it against each case value in order. When a match is found, the corresponding statement list executes and control passes to the statement after END_CASE. If no match is found and an ELSE clause is present, its statement list executes.

Unlike C-style switch statements, there is no fall-through between cases.

Example

See Also

• IF — conditional branching