1. Quick Comparison
2. If Statements
3. While Loops
4. For Loops
5. Modulus
   1. Modulus in Python
   2. Modulus in JavaScript

In Python if, while and for don't require parentheses, have colons, and use indentation to define the body. In JavaScript, these statements do require parentheses, don't have a colon, and require curly braces to define the body. If you don't write curly braces, the next statement will be considered the body.

temperature = int(input('what is the temperature?'))
if temperature >= 80:
    print('hot')
elif temperature >= 70:
    print('warm')
elif temperature >= 60:
    print('chilly')
else:
    print('cold') 

let temperature = prompt('what is the temperature?')
if (temperature >= 80) {
    alert('hot')
} else if (temperature >= 70) {
    alert('warm')
} else if (temperature >= 60) {
    alert('chilly')
} else {
    alert('cold')
}

In Python, while loops don't need parentheses and use a colon and indentation.

i = 0
while i < 10:
    print(i)
    i += 1

In JavaScript while loops need parentheses and use curly braces.

let i = 0
while (i < 10) {
    console.log(i)
    i += 1
}

In Python, for loops are structured very differently:

for i in range(10):
    print(i)

The three parts of a JavaScript for loop are the initialization, condition, and increment.

for (let i=0; i<10; ++i) {
    console.log(i);
}

Modulus works differently in each language for negative numbers.

for i in range(-4, 5):
    print(f'{i}%3={i%3}')

-4%3=2
-3%3=0
-2%3=1
-1%3=2
0%3=0
1%3=1
2%3=2
3%3=0
4%3=1

for (let i=-4; i<5; ++i) {
    console.log(i+'%3='+(i%3));
}

-4%3=-1
-3%3=0
-2%3=-2
-1%3=-1
0%3=0
1%3=1
2%3=2
3%3=0
4%3=1