Campbell CR800 Dokumentacja Pobierz pdf (Strona 249)

Section 9. Program Control Instructions

If ... Then ... Else Statement

Allows conditional execution, based on the evaluation of an expression.

Syntax 1

If condition Then thenpart [Else elsepart]

Syntax 2

If condition1 Then

[statementblock-1]

[ElseIf condition2 Then

[statementblock-2] ]

[Else

[statementblock-n] ]

EndIf

Syntax 1 Description

The single-line form is often useful for short, simple conditional tests. Syntax

1 has these parts:

Part Description

If Begins the simple If...Then control structure.

condition An expression that evaluates true (nonzero) or false (0 and

Null).

Then Identifies actions to be taken if condition is satisfied.

thenpart Statements or branches performed when condition is true.

Else Identifies actions taken if condition is not satisfied. If the

Else clause is not present, control passes to the next

statement in the program.

elsepart Statements or branches performed when condition is false.

The thenpart and the elsepart fields both have this syntax:

{statements | [GoTo] linenumber | GoTo linelabel }

The thenpart and elsepart syntax has these parts:

Part Description

statements One or more CRBasic statements, separated by colons.

Note You can have multiple statements with a condition, but they

must be on the same line and separated by colons, as in the

following statement:

If A > 10 Then A = A + 1 : B = B + A : C = C + B

Syntax 2 Description

The block form of If...Then...Else provides more structure and flexibility than

the single-line form and is usually easier to read, maintain, and debug. Syntax

2 has these parts:

9-9

1 2 ... 244 245 246 247 248 249 250 251 252 253 254 ... 323 324

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Campbell CR800 Dokumentacja Strona 249