Typescript: Is there a simple way to convert an array of objects of one type to another

Question

So, I have two classes

Item { name: string; desc: string; meta: string}  ViewItem { name: string; desc: string; hidden: boolean; } 

I have an array of Item that needs to be converted into an array of ViewItem. Currently, I am looping through the array using for, instantiating ViewItem, assigning values to attributes and pushing it to the second array.

Is there a simple way to achieve this using lambda expressions? (similar to C#) Or is there any other means?

Answer 1

You haven't showed enough of your code, so I'm not sure how you instantiate your classes, but in any case you can use the array map function:

class Item {     name: string;     desc: string;     meta: string }  class ViewItem {     name: string;     desc: string;     hidden: boolean;      constructor(item: Item) {         this.name = item.name;         this.desc = item.desc;         this.hidden = false;     } }  let arr1: Item[]; let arr2 = arr1.map(item => new ViewItem(item)); 

(code in playground)

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Edit

This can be shorter with Object.assign:

constructor(item: Item) {     Object.assign(this, item); } 

Answer 2

you can do use something like this.

const newdata = olddata.map((x) => {         return { id: Number(x.id), label: x.label };       }); 

as the converted column will be mapped to the newdata array.