The difference between item[key] vs item.id in TS/JS
This blog is back to basics in TS/JS. The difference between item[key] and item.id. There is a way to access a property of the object
item.id is a Static Property Access:
- fixed property name that is explicitly defined in the object. - known at compile time
- Example
const item = { id: 1, name: "Project A" };console.log(item.id); // Output: 1
item[key] is a Dynamic Property Access:
- This allows you to dynamically access an object's properties based on the key value. - not known at compile time and is determined dynamically at runtime
- Example
const key = "name";const item = { id: 1, name: "Project A" };console.log(item[key]); // Output: "Project A"
Note: item[key] is more flexible but less type-safe.
Another example
const isInListById = (value: number, list: { id: number }[]) => { return list.some(item => item.id === value);};const list = [ { id: 1, name: "Project A" }, { id: 2, name: "Project B" }];console.log(isInListById(1, list)); // Output: true
#javascript #typescript #StaticPropertyAccess #DynamicPropertyAccess