Terms

Question 1

Statically typed

Answer 1

Data type of each variable must be known at compile time.

Question 2

What are Rusts four primary scalar types?

Answer 2

Integers, Floating points, Characters, Booleans.

Question 3

What is an integer data type?

Answer 3

A number without a fractional part.

Question 4

What is a panic() in rust?

Answer 4

When a program exits with an error.

Question 5

How does Rust handle integer overflow?

Answer 5

At runtime when debugging: it panics() At runtime on release, it wraps (i.e., from 255 -> 1).

Question 6

What memory does a Boolean value take up?

Answer 6

One byte, nom.

Question 7

How are character literals differentiated from string literals in Rust?

Answer 7

Strings use double quotes, characters use single quotes.

Question 8

What is an approximate CS definition of a tuple?

Answer 8

An immutable ordered sequence of elements.

Question 9

How do arrays differ from tuples in Rust?

Answer 9

They are declared with square brackets instead of round, all elements are of the same data type.

Question 10

What is the difference between a statement and an expression?

Answer 10

A statement is an instruction to perform some action, whereas an expression evaulates code to a resulting value.

Question 11

What happens at the e.o.l with a statement or expression in Rust?

Answer 11

Statements end in a semi colon, expressions do not.

Question 12

What is the difference between shadowing and mutability?

Answer 12

When a mutable variable is modified, the value in memory is modified. When an immutable variable is shadowed, a new memory location is used to store a new value - with the variable name. The old memory location is unused.

Question 13

What kind of loops does Rust have?

Answer 13

while, for, loop

Question 14

What is the stack?

Answer 14

A memory structure that is strictly first in last out. Push onto stack, or pop off the stack.

Question 15

What is the heap?

Answer 15

A memory structure that allows “random” storage and retrieval of allocations.

Question 16

What is allocating on the heap?

Answer 16

Find an empty (and large enough) space on the heap, mark it as being used, and return a pointer to that location.

Question 17

Is pushing onto the stack or allocating on the heap faster?

Answer 17

Pushing on the stack!

Question 18

What calling a function with arguments, what memory structure is used?

Answer 18

The stack. Any arguments and local variables are pushed onto the stack.

Question 19

What is boilerplate code?

Answer 19

Refers to code that must be include with little to no alteration.

Question 20

What is verbose code?

Answer 20

Containing more explanation than necessary, or more code than necessary.

Question 21

What is meant by a string “literal”?

Answer 21

Text that is hard coded in the program.

Question 22

What is RAII?

Answer 22

Resource allocation is initialization. The curly bracket at the end of a code block automatically drops any variables that go out of scope from memory.

Question 23

Will this code run? Why?

fn main() {

let hello = String::from(“hi”);

say_hi(hello);

println!(“saying {} again”, hello);

}

fn say_hi(hello: String) {

println!(“{}”, hello);

}

Answer 23

Nope, because hello is moved to the scope of say_hi and not returned. Once a variable-value binding goes out of scope it is dropped from memory.

Question 24

What is a String slice?

Answer 24

A reference to a part of a string! Initialized and declared with:

&s[0..5]

Where the brackets contain the index range (upper bound exclusive).

Question 25

How can the length of a string be found?

Answer 25

Using:

variable_name.len()