JavaScript - Closures
function makeAdder(x) {
return function(y) {
return x + y;
};
}
var add5 = makeAdder(5);
var add10 = makeAdder(10);
console.log(add5(2)); // 7
console.log(add10(2)); // 12
//=====
//add5 and add10 are both closures.
//They share the same function body definition, but store different lexical environments.
//In add5's lexical environment, x is 5, while in the lexical environment for add10, x is 10.