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ZBasic Language Reference 36 ZX Microcontroller Family If i > 3 Then Call PutPin(12, zxOutputLow) ElseIf (i > 0) Then j = 0 Else j = 55 Call PutPin(12, zxOutputHigh) End If Note that the conditional expression is not required to be enclosed in parentheses. Many programmers are accustomed to other languages where they are required and therefore do so out of habit. Others believe that the parentheses improve the readability and use them for that reason. You’re free to adopt whichever practice suits you. One other comment on style is in regard to indentation. The examples used in this document indent the statements within compound statements like If-Then-Else in order to improve readability. The compiler ignores spaces and tabs except to the extent that they separate identifiers, keywords, etc. You’re free to adopt any indentation style that you deem appropriate. There is no fixed limit on how deeply If-Then statements may be nested. The actual limit is governed by how much memory is available to the compiler. For all practical purposes, there is no limit. 2.5.11 Single-line If-Then Statement Sometimes, it is convenient to express conditional logic concisely using a single-line If statement. The form is similar to the multi-line form except that the Else If clause is not supported and there is no End If. The syntax of a single-line If statement is: If <boolean-expression> Then <statement> [ Else <statement> ] The <boolean-expression> element is the same as described in the previous section. The <statement> element represents one ZBasic statement such as an assignment statement or a Call statement. Note, that it is permissible to for <statement> to be multiple statements each separated from the next by a colon. Moreover, the line continuation character may be used to distribute the <statement> over multiple lines. Examples If (a > b) Then a = b If (a > b) Then a = b Else b = 10 If flag Then flag = False : Call MySub(25) BasicX Compatibility Note The single-line If statement is not supported in BasicX compatibility mode. 2.5.12 Select-Case Statement The Select-Case compound statement is a multi-way branch statement that can be used in place of an If- Then-ElseIf chain is certain situations. The syntax is shown below.