JS Map Methods
Has distinguishes a missing key from a key whose value is undefined. Delete removes an entry.
Where to run this
This example uses the JavaScript console playground. Select Run to execute it; the example does not run on this lesson page.
A practical example
const stock = new Map([["tape", 3], ["glue", 0]]);
console.log(stock.has("glue"));
stock.delete("tape");
console.log(stock.size);
What happens
Glue exists even though its count is zero; one entry remains.