minte9

REMEMBERS

Exponentiation

 
/**
 * The exponentiation operator a ** b raises a to the power of b.
 * A in maths, square root is an exponentiation by 1/2 
 */

console.log(2 ** 3); // 8
console.log(4 ** 1/2); // 2 (power of 1/2 is the same as square root)
console.log(8 ** 1/3); // 2 (power of 1/3 is the same as cubic root)

console.log(2 ^ 3); // 1 - XOR bitwise
console.log(2 ^ 2); // 0

console.log(3 % 2); // 1 - reminder
console.log(8 % 3); // 2

Unary +

 
/**
 * The plus operator + applied to a single value, ...
 * doesn’t do anything to numbers. 
 * 
 * The need to convert strings to numbers arises very often.
 */

let a = 1;
console.log( +a ); // 1 - no effect on numbers

let flag = true;
console.log( +flag ); // 1 - convertion

let b = 0;
console.log( +b );   // 0 - convertion

let c = "2";
let d = "3";
console.log( +c + +d ); // 5

Precendence

 
/**
 * Unary pluses applied to values before the binary ones ...
 * because of their higher precedence.
 * 
 *  +     // unary
 *  **    // exponentiation
 *  *     // multiplication
 *  /     // division
 *  +     // addition
 *  -     // subtraction
 *  =     // assignment 
 * 
 * Parentheses override any precedence.
 */

let u = +"1" + +"2";

console.log(u); // 3

let a = 1 + 2 * 3;
let b = (1 + 2) * 3;

console.log(a); // 7
console.log(b); // 9