The objects I use on the client side need a unique ID. My array of objects is very small, commonly 4 items, not more.
I use this:
export class MyItem {
uniqueObjectIdentifier: number;
constructor(obj) {
this.uniqueObjectIdentifier = Math.random();
}
}
Is there something maybe javascript or angular internal that I can access instead of the handcrafted property?
You can use a Symbol.
Every symbol value returned from Symbol() is unique.
export class MyItem {
uniqueObjectIdentifier: symbol;
constructor(obj) {
this.uniqueObjectIdentifier = Symbol();
}
}
If browser support doesn't allow you to use a symbol, you can use a reference to an object instead.
export class MyItem {
uniqueObjectIdentifier: object;
constructor(obj) {
this.uniqueObjectIdentifier = {};
}
}
Symbol() or {} different from the actual var item1 = new MyItem(); item2 = new MyItem()
{} and new MyItem().
In TypeScript you can do this:
export class MyItem {
static currentId: number = 0;
uniqueObjectIdentifier: number;
constructor(obj) {
this.uniqueObjectIdentifier = MyItem.currentId++;
}
}
In JavaScript ES6:
export class MyItem {
constructor(obj) {
this.uniqueObjectIdentifier = MyItem.currentId++;
}
}
MyItem.currentId = 0;
Or you can use unexported, module scoped variable to hold the counter:
let currentId = 0;
export class MyItem {
constructor(obj) {
this.uniqueObjectIdentifier = currentId++;
}
}
That way currentId can't be modified from outside the module.
angular,typescript, orecmascript-6, but is this the same question as this?Math.random()?Math.random()is not unique. In javascript it's actually pseudo random, so it will repeat itself eventually.