便捷方法(Convenience methods)#
n8n 提供了这些方法，以便更轻松地在 表达式 中执行常见任务。
🌐 n8n provides these methods to make it easier to perform common tasks in expressions.
Python 支持
你可以在代码节点中使用 Python。在表达式中无法使用它。
| Method | Description | Available in Code node? |
|---|---|---|
$evaluateExpression(expression: string, itemIndex?: number) |
Evaluates a string as an expression. If you don't provide itemIndex, n8n uses the data from item 0 in the Code node. |
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$ifEmpty(value, defaultValue) |
The $ifEmpty() function takes two parameters, tests the first to check if it's empty, then returns either the parameter (if not empty) or the second parameter (if the first is empty). The first parameter is empty if it's:
|
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$if() |
The $if() function takes three parameters: a condition, the value to return if true, and the value to return if false. |
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$max() |
Returns the highest of the provided numbers. | |
$min() |
Returns the lowest of the provided numbers. | |
| Method | Description |
|---|---|
_evaluateExpression(expression: string, itemIndex?: number) |
Evaluates a string as an expression. If you don't provide itemIndex, n8n uses the data from item 0 in the Code node. |
_ifEmpty(value, defaultValue) |
The _ifEmpty() function takes two parameters, tests the first to check if it's empty, then returns either the parameter (if not empty) or the second parameter (if the first is empty). The first parameter is empty if it's:
|