CODEWITHSUNDEEP
typescripttypescript2.0
Nick Mehrdad Babaki
Nick Mehrdad Babaki

Reputation: 12565

Complicated Types in Typescript

I have a code as below:

ngOnChanges(changes: {[property: string]: SimpleChange }) {
let change = changes["bgClass"];
let classList = this.element.nativeElement.classList;

I don't understand what this part means exactly:

changes: {[property: string]: SimpleChange }

Upvotes: 0

Views: 66

Answers (1)

user6749601
user6749601

Reputation:

It means that you have an object-array [] named changes, consisting of several Sub-Objects {} of type SimpleChange, that can be addressed by string [<object-name>: type].

changes: {[property: string]: SimpleChange }

So you could have something like this (just an example)

let changeClass = changes["bgClass"]; // you get the object named bgClass
let changeState = changes["disabled"]; // you get the object named disabled
...

This way you can examine what exactly changed and fired the change event.

Upvotes: 2

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