:markdown

A dependency injection container used for resolving dependencies.

An `Injector` is a replacement for a `new` operator, which can automatically resolve the constructor dependencies.

In typical use, application code asks for the dependencies in the constructor and they are resolved by the

`Injector`.

## Example:

Suppose that we want to inject an `Engine` into class `Car`, we would define it like this:

```javascript

class Engine {

}

class Car {

}

```

Next we need to write the code that creates and instantiates the `Injector`. We then ask for the `root` object,

`Car`, so that the `Injector` can recursively build all of that object's dependencies.

```javascript

main() {

var injector = Injector.resolveAndCreate([Car, Engine]);

// Get a reference to the `root` object, which will recursively instantiate the tree.

var car = injector.get(Car);

}

```

Notice that we don't use the `new` operator because we explicitly want to have the `Injector` resolve all of the

object's dependencies automatically.

h2 Members

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h3 constructor

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constructor(bindings:List<ResolvedBinding>, parent:Injector, defaultBindings:boolean, [object Object], [object Object], [object Object])

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h3 asyncGet

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asyncGet(token, [object Object])

:markdown

Retrieves an instance from the injector asynchronously. Used with asynchronous bindings.

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h3 createChildFromResolved

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createChildFromResolved(bindings:List<ResolvedBinding>, [object Object])

:markdown

Creates a child injector and loads a new set of <a href="angular2/di/ResolvedBinding-class"><code>ResolvedBinding</code></a>s into it.

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h3 fromResolvedBindings

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fromResolvedBindings(bindings:List&lt;ResolvedBinding&gt;, {defaultBindings=false}={}, [object Object], [object Object])

:markdown

Creates an injector from previously resolved bindings. This bypasses resolution and flattening. This API is the

recommended way to construct injectors in performance-sensitive parts.

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h3 get

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get(token, [object Object])

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Retrieves an instance from the injector.

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h3 getOptional

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getOptional(token, [object Object])

:markdown

Retrieves an instance from the injector.

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h3 resolve

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resolve(bindings:List, [object Object])

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Turns a list of binding definitions into an internal resolved list of resolved bindings.

A resolution is a process of flattening multiple nested lists and converting individual bindings into a

list of <a href="angular2/di/ResolvedBinding-class"><code>ResolvedBinding</code></a>s. The resolution can be cached by `resolve` for the <a href="angular2/di/Injector-class"><code>Injector</code></a> for

performance-sensitive code.

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h3 resolveAndCreate

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resolveAndCreate(bindings:List, {defaultBindings=false}={}, [object Object], [object Object])

:markdown

Resolves bindings and creates an injector based on those bindings. This function is slower than the

corresponding `fromResolvedBindings` because it needs to resolve bindings first. See `resolve` for the

<a href="angular2/di/Injector-class"><code>Injector</code></a>.

Prefer `fromResolvedBindings` in performance-critical code that creates lots of injectors.

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h3 resolveAndCreateChild

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resolveAndCreateChild(bindings:List, [object Object])

:markdown

Creates a child injector and loads a new set of bindings into it.

A resolution is a process of flattening multiple nested lists and converting individual bindings into a

list of <a href="angular2/di/ResolvedBinding-class"><code>ResolvedBinding</code></a>s. The resolution can be cached by `resolve` for the <a href="angular2/di/Injector-class"><code>Injector</code></a> for

performance-sensitive code.