JS Fundamentals

Question 1

To declare a variable

Answer 1

Use var, let, const

Question 2

=

Answer 2

Assignment Operator

Question 3

Another word for the starting value of a variable

Answer 3

The variable is initialized with [blank]

Question 4

mathematical assignment operators

Answer 4

+=, -=, *=, /=
perform a mathematical operation to the variable, then reassign that value to the variable
ex: z += 1 is the same as z = z + 1

Question 5

Increment and Decrement Operator

Answer 5

++, –
another mathematical assignment operator
the variable’s value is updated and assigned as the new value of that variable
increment operator - increases the value of the variable by 1
decrement operator - decreases the value of the variable by 1
ex:
let a = 10;
a++; // => a = 11;

Question 6

String Interpolation

Answer 6

interpolate (or insert) variables into strings using template literals
ex: const myPet = 'armadillo';
console.log(`I own a pet ${myPet}.`);
- template literal is wrapped by backticks
- Inside the template literal, you'll see a placeholder, ${myPet}. The value of myPet is inserted into the template literal
- When we interpolate `I own a pet ${myPet}.`, the output we print is the string: 'I own a pet armadillo.'
Using template literals, you can more easily tell what the new string will be. You also don't have to worry about escaping double quotes or single quotes.

Question 7

typeof operator

Answer 7

checks the value to its right and returns, or passes back, a string of the data type

ex: const unknown1 = ‘foo’;
console. log(typeof unknown1); // Output: string

Question 8

Conditional Statements

Answer 8

checks specific condition(s) and performs a task based on the condition(s)
if and if/else statements

Question 9

Comparison Operators

Answer 9

operators to compare values
>, =, <=, ===, !==
evaluate to either true or false

Question 10

Logical Operators

Answer 10

&&, ||