Adobe 38043740 Developing Applications - Page 120

DEVELOPING COLDFUSION 9 APPLICATIONS 115 The CFML Programming Language if(score GT 1) result = "positive"; else result = "negative"; CFScript does not include an elseif statement. However, you can use an if statement immediately after an else statement to create the equivalent of a cfelseif tag, as the following example shows: if(score GT 1) result = "positive"; else if(score EQ 0) result = "zero"; else result = "negative"; As with all conditional processing statements, you can use curly brackets to enclose multiple statements for each condition, as follows: if(score GT 1) { result = "positive"; message = "The result was positive."; } else { result = "negative"; message = "The result was negative."; } Note: Often, you can make your code clearer by using braces even where they are not required. Using switch and case statements The switch statement and its dependent case and default statements have the following syntax: switch (expression) { case constant: [case constant:]... statement(s) break; [case constant: [case constant:]... statement(s) break;]... [default: statement(s)] } Use the following rules and recommendations for switch statements: • You cannot mix Boolean and numeric constant values in a switch statement. • Each constant value must be a constant (that is, not a variable, a function, or other expression). • Multiple caseconstant: statements can precede the statement or statements to execute if any of the cases are true. This lets you specify several matches for one code block. • No two constant values can be the same. • The statements following the colon in a case statement block do not have to be in curly brackets. If a constant value equals the switch expression, ColdFusion executes all statements through the break statement. • The break statement at the end of the case statement tells ColdFusion to exit the switch statement. ColdFusion does not generate an error message if you omit a break statement. However, if you omit it, ColdFusion executes all the statements in the following case statement, even if that case is false. In nearly all circumstances, this is not what you want to do. • You can have only one default statement in a switch statement block. ColdFusion executes the statements in the default block if none of the case statement constants equals the expression value. Last updated 1/20/2012