console.clear();

let a;

console.log(a);

a = 15;

console.log("Ma variable a = " + a);

let b = 9;

console.log("Ma variable b = " + b);

console.log(`15 + 9 = ${a+b}`);

console.log(`15 - 9 = ${a-b}`);

console.log(`15 * 9 = ${a*b}`);

console.log(`15 / 9 = ${a/b}`);

a = "Bonjour";

b = " les amis";

console.log(a.concat(b))

a = true;

b = false;

console.log("true AND false = " + (a & b));

console.log("true OR false = " + (a | b));

a = new Date();

b = new Date();

b.setDate(-61);

console.log(a.toLocaleString());

console.log(a.toLocaleDateString());

console.log(b.toLocaleString());

console.log(b.toLocaleDateString());

a = Math.PI;

b = "Bonjour";

let c = true;

let d = new Date();

console.log(a + " est de type " + typeof a);

console.log(b + " est de type " + typeof b);

console.log(c + " est de type " + typeof c);

console.log(d.toLocaleDateString() + " est de type " + typeof d);