Introduction

FEEL expressions are powerful and can be used for various cases.

This section is split into expressions based on their operational data type:

• Boolean
• String
• Numeric
• List
• Context
• Temporal

The following sections cover more general areas that are not restricted to one data type:

• Variables
• Control flow
• Functions
• Error handling

Comments

An expression can contain comments to explain it and give it more context. This can be done using Java-style comments: // to the end of line, or /*.... */ for blocks.

// returns the last item
[1,2,3,4][-1]

/* returns the last item */
[1,2,3,4][-1]

/*
 * returns the last item
 */
[1,2,3,4][-1]

Parentheses

Parentheses ( .. ) can be used in expressions to separate different parts of an expression or to influence the precedence of the operators.

(5 - 3) * (4 / 2)

x < 5 and (y > 10 or z > 20)

if (5 < 10) then "low" else "high"