More forEach and filter

// array.filter(conditionFunction); // returns a new array of items that match the condition

var numbers = [5, 10, 35, 12, 45];

var higherNumbers = numbers.filter( function(item, index, array) {
	if (item > 30) {
		return true; // explicitly return true to include item in the result
	} else {
		return false; // explicitly return false to exclude item
	}
});

console.log( higherNumbers ); // [35, 45]



function isHighNumber(number) {
	return number > 30; // directly return the condition result (true/false)
}

var higherNumbers = numbers.filter(isHighNumber);

console.log( higherNumbers ); // [35, 45]

//

var shorter = numbers.filter( (item)=> item > 30 );

const apes = ['Orangutans', 'Gorilla', 'Chimpanzees', 'Humans'];

// classic foreach method with anonymous function
apes.forEach( function(ape) {
  return console.log('1', ape);
});

// a regular function
function printApe(ape) {
  return console.log('2', ape);
}

// array.forEach method with named function passed in
apes.forEach( printApe ); // does this feel mysterious?

// an "arrow" function as an "anonymous" callback function 
apes.forEach( (ape) => console.log('3', ape) );
// implicit return
// (starting to be the default in MDN documentation)

// you can leave out the (arg) if there's only one
apes.forEach( ape => printApe(ape) );

// if there is no argument you need empty parenthesis
apes.forEach( () => console.log('4') );

// if you open up a codeblock, you need to explicitly return again
apes.forEach( (ape)=> {
  return console.log('5', ape);
});

// What ^ is happening here exactly?
apes.forEach( function(ape) {
  return console.log('6', ape);
});
// what is different about the syntax?