Composition over Inheritance

Closures

Closures is (a fancy term for) a function that remembers outside things that are used inside const createPrinter() { const name = 'Alex' const printName = () => { console.log(name) } return printName } const myPrinter = createPrinter() myPrinter() // Alex This function that was return from from createPrinter function is called a closure . // Here is printName Closure is a combination of a function and the environment where it was declared .

Array.fill()

Caveat: If you .fill() an Array with an object, all elements refer to the same instance (i.e., the object isn’t cloned) So if you do something like: let a = Array(3).fill([]) // create an array named a and fill it with 3 empty array a[2].push('poop') // push new value to the element array at index 2 expect [ [], [], [2]] But because all element refer to the same instance, so the result is: [[2], [2], [2]] More details here: https://2ality.com/2018/12/creating-arrays.html

Callback function

Là một function mà ta truyền vào trong một function khác (như tham số - as an argument) fucntion( function() { ... }) {...}

Tan's Notes

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