1// var declares a variable, meaning its value will vary. 
2// const declares a constant, meaning its value will remain 
3// consistant and not change. 
4// If your variable changes throughout the program or website, 
5// declare it using a var statement. 
6// Otherwise, if its value does not change, declare it using 
7// a const statement. 
8
9const myConst='A const does not change.';
10
11var myVar='A var does change.';
12
13var myVar=2;

1var makes real ice cubes that rattle around in New York
2let makes real ice cubes in Manhatten 
3const is like let but the ice cubes never change because they are plastic

1    var greeter;
2    console.log(greeter); // greeter is undefined
3    greeter = "say hello"
4