# Expressions: Lamda invocations

## 

Lambdas are very much like functions—constructed as described in [Lamba Constructors](/guides/orchestration/getting-started/expressions/constructors#lambda-constructors).

The syntax for invoking a lambda is similar to the function invocation syntax:

```js
@(lambda)(arg1, ...)
```

where *lambda* is an expression returning a lambda value, and *arg1*, ... are comma-separated expressions that calculate arguments to pass to the lambda.

When invoking a lambda, its body expression will be evaluated with the parameters bound to arguments passed at the invocation point. For example, consider the following expression: `let twice=(x)=>2*x return @(twice)(8)`. The lambda invocation expression here, `@(twice)(8)`, will invoke the lambda value constructed by `(x)=>2*x`  since this is the value bound to variable twice. This invocation will bind the value 8 to argument x, and then evaluate and return the expression `2*x` —which will yield 16.