Declaring Variables Lab

The keyword 'const' is uses when the variable will not be assigned a new value.

const a = 10;
prn("a: " + a);

//not allowed
//a = 20;

The keyword 'let' is uses when the variable will be assigned a new value.

let a;

a = 10;
prn("a: " + a);

//allowed
a = 20;
prn("a: " + a);

Depending on our logic, we may prefer to declare all variables at the top of a method, to lighten the logic code. We would use 'let'.

let a, b, sum;
a = 10;
b = 2;
sum = a + b;
prn('sum: ' + (a + b));

This is to contrast the "declarations first" style in the previous snippet. Simple calcs have been used for the example purposes.

const a = 10;
const b = 2;
const sum = a + b;
prn('sum: ' + (a + b));