Question

131

what does `(this as any)` mean in this typescript snippet?

rated 0 times [ 137] [ 6] / answers: 1 / hits: 31472 / 7 Years ago, thu, march 2, 2017, 12:00:00

I meet this code and do not understand exactly what it does :

public uploadItem(value:FileItem):void {

    let index = this.getIndexOfItem(value);

    let item = this.queue[index];

    let transport = this.options.isHTML5 ? '_xhrTransport' : '_iframeTransport';

    item._prepareToUploading();

    if (this.isUploading) {

      return;

    }

    this.isUploading = true;

    (this as any)[transport](item);

  }

Can anyone explain what does this (this as any) statement do?

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diamondlauryna

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4 Years ago

answered 7 Years ago reed · Accepted Answer

(this as any ) is just a Type Assertion that works on dev/compiling time and has no side effects on run time because it is purely a Typescript thing. It can be useful if something related to this like this[whatever] which outputs a TS error because whatever is not defined inside the this TS type. So, this error can be suppressed with (this as any)[whatever]

Also (this as any) is the equivalent to (<any> this)

Note to mention: --suppressImplicitAnyIndexErrors as a compiler option suppresses those kind of possible errors.