for(i=0; i<5; i++) {
	setTimeout(function() {
		console.log('wrong output: ', i);
	}, 100); //5
}

//1. function: copy value
function fn(i) {
    return function() {
	console.info(i);
    }
}
for(i=0; i<5; i++) {
	setTimeout(fn(i), 100);
}

//2. bind: create new function, same as (1)
//The bind() method creates a new function that, when called, has its this keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called.
for(i=0; i<5; i++) {
	setTimeout(console.log.bind(console, i), 100);
}

//3. IIFE, pass value instead of reference
for(i=0; i<5; i++) {
	(function(i) {
		setTimeout(function() {
			console.log(i);
		}, 100);
	}(i));
}

//4. inside setTimeout, do the IIFE:
for(i=0; i<5; i++) {
    	setTimeout((function(i) {
            return function() {
		console.log(i);
            }
	}(i)), 100);
}

//5. use call() to pass value instead of reference
//The call() method calls a function with a given this value and arguments provided individually.
for(i=0; i<5; i++) {
	setTimeout(function() {
		console.log(i);
	}.call(i), 100);
}

//6. use apply() to pass value instead of reference
//The apply() method calls a function with a given this value and arguments provided as an array (or an array-like object).
for(i=0; i<5; i++) {
	setTimeout(function() {
		console.log(i);
	}.apply(i), 100);
}