VXI VT1422A User Manual

Page 221

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Creating and Running Algorithms 219

Chapter 6

Note that in BASIC the boolean_expression is delimited by the IF and the
THEN keywords. In 'C', the parentheses delimit the expression. In 'C',
the ")" is the implied THEN. In BASIC, the END IF keyword terminates a
multi-line IF. In 'C', the if is terminated at the end of the following statement
when no else clause is present or at the end of the statement following the
else clause. Figure 6-6 shows examples of these forms.

Note that in 'C' "else" is part of the closest previous "if" statement.
So the example:

if( x ) if( y ) z = 1; else z = 2;

executes like:

not like:

if( x ){

if( x ){

if( y ){

if ( y ){

z = 1;

z = 1;

}

}

else{

}

z = 2;

else{

}

z = 2;

}

}

Simplest form (used often)

Two-line form (not recommended; use
multiple line form instead)

Multiple line form (used often)

Multiple line form with else (used often)

Comments

if(boolean_expression) statement;

if(boolean_expression)

statement;

if(boolean_expression){

statement;
statement;
statement;

}

if(boolean_expression)
{

statement;
statement;

}
else
{

statement;

}

'C' Syntax

Figure 6-5. The If Statement 'C' versus BASIC

IF boolean_expression THEN
statement

IF boolean_expression THEN

statement

END IF

IF boolean_expression THEN

statement
statement
statement

END IF

IF boolean_expression THEN

statement
statement

ELSE

statement

END IF

BASIC Syntax

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