implementMap&Filter.js

/*TO DO:
NEXT, AT WORK: (1) append RULE + ARRAYITEM (2) use eval() to check an appended string in the loop 
(3) OUTPUT RESULTS
*/

// rule: A function that returns a boolean.
let flitter = (things, rule) => {

		// result: Becomes true in loop when the rule matches.
		// stringOfRule: Holds things[i] array member, headed for appending.
		let result = false;
		let outThings = [];
		console.log(`Rule result, by item:`);
		for (let i = 0; i <= things.length - 1 ; i++){
			result = rule(things[i]);
/*			console.log(`# ${i} ${result}`);
*/			if (result){
				outThings.push(things[i]);
			}
 	}
			return outThings;
};

let amp =(things, verb) => {
	let outThings = [];
	for (let i=0; i <= things.length - 1; i++){
		outThings.push("foo");
	}
	return outThings;
}

const ELEMENTS = ["oxygen-8", "cooties", "boron-5", "titanium-15"];
const CHECK =(x)=>{return x == "cooties"} ;

const NUMBERS = [ 1, 2, 3, "four", null, undefined, NaN ];
const isTiny =(x)=> {return x === 1 | x < 2 ;}

const isBreathing =()=> { return true;}

console.log("Test it three times.");

// returns 1, 0, 0, 1, 0, 0  
// Why not T/F??     And why didnt "one" get coerced (by ==)? 
console.log(flitter(NUMBERS, isTiny));
console.log(flitter(NUMBERS, isBreathing));

let funky = function (x) {
	return x.length;
}
console.log(`La amp made this: ${amp(ELEMENTS, funky)}`);
console.log(`La amp made this: ${amp(NUMBERS, funky)}`);


/**
Coding Interview byte-ebook says:
IMPLEMENT MAP  &  FILTER
They are both functions that take in a list, perform some operation on that list without changing the original list, and then return a new lists. The functions do not change any other variables and do not touch anything else except those lists they were given.
Map: applY the function to each element in the list   ARGS: list and function
Filter returns a new list where every element in the original list passes the conditional (returns true).  ARGS: list and conditional
December 17, 2018
@mistergenest
Dev Diary:  7:28am
To Do: Pass in a joiner function that joins with dashes

*/

/*
  
*/