Introduction to JavaScript II

• if-else
• switch case
• for
• for…in
• for…of
• while
• do…while

// conditional statements
// if else
let hour = 8;
if (hour >= 6 && hour <= 12){
    console.log("Good morning!");
} 
else if (hour > 12 && hour <= 18){
    console.log("Good afternoon!");
}
else
    console.log("Good evening!");

// switch case
let role = 'guest';
switch (role){
    case 'guest':
        console.log('Guest User');
        break;
    
        case 'moderator':
        console.log('Moderator User');
        break;
    
        default:
            console.log('Unknown User');
}

/* // loops * 5
// for; while; do...while;for...in;for...of */
// for 
console.log('for loop:')
for (let i = 0; i <= 5; i++){
    if (i%2 !== 0) console.log(i)
}

// while
console.log('while loop:')
let i = 0;
while (i <= 5){
    if (i%2 !==0) console.log(i);
    i++;

}

// do-while
console.log('do-while loop:')
let j = 0;
do {
    if (j % 2 !==0 ) console.log(j);
    j++;
} while (j <= 5);

// words (condition){
//     statement
// }

// for .. in: iterate all properties of object or all index of array elements.
const person1 = {
    name: 'Joey',
    age: 100
};
for (let key in person){
    console.log(key,person[key]); // cannot use person.key
};

const colors = ['red','green','blue']
for (let index in colors){
    console.log(index,colors[index]);
}

// for...of: iterate atoms of array
for (let color of colors)
    console.log(color)

// break: end the whole loop
// continue: end current loop

Thanks for @Mosh‘s great video tutorials.