More on the book. What i learnt today:
Closure:
being able to reference a specific instance of a local binding in an enclosing scope. A function that references bindings from local scopes around it is called a closure.
A pure function
a specific kind of value-producing function that not only has no side effects but also doesn’t rely on side effects from other code—for example, it doesn’t read global bindings whose value might change. A pure function has the pleasant property that, when called with the same arguments, it always produces the same value
Array Methods
includes()
- checks if a given value exists in the array.
shift()
- removes the first(zero index) item from an array.
unshift()
- adds a item at the front(zero index) of an array
indexOf()
- searches through the array from the start to the end and returns the index at which the requested value was found
lastIndexOf()
- searches through the array from the end(last item)
trim ()
- removes whitespace (spaces, newlines, tabs, and similar characters) from the start and end of a string
...
Spread Syntax - expands or spreads out an array, passing its elements as separate arguments.
Looping through arrays using let
item of
items.
for (let item of items) {
console.log(item);
}
Math Object functions
Math.floor()
- rounds down
Math.ceil()
- rounds up
Math.round()
- rounds to the nearest whole number
Math.abs()
- takes the absolute value of a number, Negates a negative.
What is JSON?
A serialization format. Serialization means converting to a a flat description.
Json Methods
JSON. parse()
Converts a JSON string to a JavaScript object
JSON. stringify()
Converts a JavaScript object to a JSON string
That's it for Day 80
I'll continue with the book tommorrow
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