Conditionals

if Statement

const isMailSent = true;

if (isMailSent) {
  console.log("Mail sent to recipient");
}

Ternary Operator

var x = 1;

// => true
result = x == 1 ? true : false;

Operators

true || false; // true
10 > 5 || 10 > 20; // true
false || false; // false
10 > 100 || 10 > 20; // false

Logical Operator &&

true && true; // true
1 > 2 && 2 > 1; // false
true && false; // false
4 === 4 && 3 > 1; // true

Comparison Operators

1 > 3; // false
3 > 1; // true
250 >= 250; // true
1 === 1; // true
1 === 2; // false
1 === "1"; // false

Logical Operator

let lateToWork = true;
let oppositeValue = !lateToWork;

// => false
console.log(oppositeValue);

Nullish coalescing operator ??

null ?? "I win"; //  'I win'
undefined ?? "Me too"; //  'Me too'

false ?? "I lose"; //  false
0 ?? "I lose again"; //  0
"" ?? "Damn it"; //  ''

else if

const size = 10;

if (size > 100) {
  console.log("Big");
} else if (size > 20) {
  console.log("Medium");
} else if (size > 4) {
  console.log("Small");
} else {
  console.log("Tiny");
}
// Print: Small

switch Statement

const food = "salad";

switch (food) {
  case "oyster":
    console.log("The taste of the sea");
    break;
  case "pizza":
    console.log("A delicious pie");
    break;
  default:
    console.log("Enjoy your meal");
}

== vs ===

0 == false; // true
0 === false; // false, different type
1 == "1"; // true,  automatic type conversion
1 === "1"; // false, different type
null == undefined; // true
null === undefined; // false
"0" == false; // true
"0" === false; // false

The == just check the value, === check both the value and the type.

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