I conducted the following experiment, and discovered that 'delete' can be used to remove a key-value pair. My question is: is this the 'proper' way to do it?

let myMap:{[key:string]:string} = {};

myMap["hello"] = "world";
console.log("hello="+myMap["hello"]); // it prints 'hello=world'

delete myMap["hello"];
console.log("hello="+myMap["hello"]); // it prints 'hello=undefined'

I conducted the following experiment, and discovered that 'delete' can be used to remove a key-value pair. My question is: is this the 'proper' way to do it?

let myMap:{[key:string]:string} = {};

myMap["hello"] = "world";
console.log("hello="+myMap["hello"]); // it prints 'hello=world'

delete myMap["hello"];
console.log("hello="+myMap["hello"]); // it prints 'hello=undefined'

• javascript
• typescript
• dictionary
• key-value

Share Improve this question Follow asked Dec 28, 2017 at 8:41 ExKExK 11122 silver badges1010 bronze badges 1

• 4 delete myMap["hello"]; is correct, I don't see any problem. – gurvinder372 Commented Dec 28, 2017 at 8:43

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1 Answer 1

Sorted by: Reset to default 3

My question is: is this the 'proper' way to do it?

This is the accurate way of doing it, but there are two caveats

• unless the property is non-configurable
• property is inherited

For example you cannot delete href property of location

delete location.href //returns false since this property cannot be deleted

Demo

var b = {
  a: 1,
  b: 2
};
Object.defineProperty(b, "c", {
  enumerable: true,
  configurable: false,
  writable: true,
  value: 3
});
delete b.c;
console.log(b); //all properties intact