Assign value not reference in Typescript method return

Question

I am working in Ionic3.

I have a function which calls another function from provider.ts and it returns an interface Object.

page.ts

getList(){
  this.localdata = this.provider.getGlobalData();
}

provider.ts

getGlobalData(){
  return this.gvData;
}

Now, any changes made to localdata are also changing gvData in provider.ts . I don't want to copy the reference, just the value. How can I do it?

Answer 1

The following snippet will return a cloned version of your object.

provider.ts

getGlobalData(){
  return JSON.parse(JSON.stringify(this.gvData));
}

---

You could also do it this way:

page.ts

getList(){
  this.localdata = JSON.parse(this.provider.getGlobalData());
}

provider.ts

getGlobalData(){
  return JSON.stringify(this.gvData);
}

Answer 2

您可以执行Object.assing({},this.provider.getGlobalData())来获取该对象的新副本。

Answer 3

Another idea is to use spread operator:

getGlobalData() {
  return { ... this.gvData};
}