Olete.in – MCQs, Mock Tests & Government Job Prep | Rust (programming language) Rust Programming Language (MCQ)

Which keyword is used to define a variable in Rust

1. const
2. let
3. f32
4. mul

✅ Correct Answer: 2

Which of the following is immutable by default in Rust but can be made mutable

1. Depends on usage
2. user defined object
3. const
4. variable

✅ Correct Answer: 4

In OOP in Rust, which keyword is used to define Interfaces?

1. pub
2. impl
3. trait
4. fn

✅ Correct Answer: 3

pub is used to define public in Rust. Are the data members in the structure public or private

1. private
2. public
3. depends on function
4. undefined

✅ Correct Answer: 1

What is the impl keyword used in Rust?

1. For Interfaces
2. For Inheritance
3. Define a class
4. Implement functionality on types

✅ Correct Answer: 4

Which code statement in Rust is used to define a BTreeMap object?

1. let mut btm = BTreeMap::new();
2. let btm = BTreeMap::new();
3. BTreeMap btm = std::collections::BTreeMap::new();
4. BTreeMap btm = BTreeMap.new();

✅ Correct Answer: 1

Which command is used to compile a Rust code?

1. rustc code.rs
2. code
3. gcc code.rs
4. gcrust code.rs

✅ Correct Answer: 1

Among const and static in Rust, which one has low memory requirement?

1. same for both
2. static
3. depends on datatype
4. const

✅ Correct Answer: 4

Rust is known to be memory safe. Which feature is the main reason for the memory safety of Rust?>

1. ownership
2. borrowing
3. reference
4. lifetimes

✅ Correct Answer: 1

Arbitrary casting is one of the most dangerous feature of Rust. Which keyword is used for it?

1. as
2. (data_type) variable
3. static
4. transmute

✅ Correct Answer: 3

To support Dynamic Sized variables, what should we use in place of "f32"?

1. ?Sized
2. list all data-types
3. Not supported in Rust
4. Use array

✅ Correct Answer: 1

Raw pointers are unsafe pointers in Rust. What is the main use of Raw pointers in Rust?

1. C type implementation
2. Low level memory control
3. Get address of variables
4. Foreign Function Interface

✅ Correct Answer: 4

In Rust, unsafe function and block allows 3 features. Which one feature is not allowed in Rust "unsafe" ?

1. Call unsafe functions
2. Dereference a raw pointer
3. turn off the borrow checker
4. Access or update a static mutable variable

✅ Correct Answer: 3

What is the use of "type" keyword in Rust?

1. User defined data type
2. dynamic sized datatype
3. template
4. alias of another type

✅ Correct Answer: 4

What is "Drop" in Rust used for?

1. option4
2. Run code and drop it if error comes
3. Run code as multi-threaded
4. Run code when variable is out of scope

✅ Correct Answer: 4

In Rust, how is a macro from the above Rust code snippet used?

1. foo!()
2. #foo
3. foo
4. foo(x)

✅ Correct Answer: 1

What is the predefined macro "unreachable!" in Rust used for?

1. warning if code not executed
2. un-implemented code snippet
3. sample code for unexpect path
4. code should never execute

✅ Correct Answer: 4

Which library does Rust use for memory allocation?

1. mimalloc
2. jemalloc
3. ptmalloc
4. tcmalloc

✅ Correct Answer: 2

Who designed Rust from scratch in 2006?

1. Graydon Hoare
2. David Flanagan
3. Yukihiro Matsumoto
4. Guido van Rossum

✅ Correct Answer: 1

What is Cargo in Rust?

1. Build system
2. Build system and package manager
3. Collection of Rust libraries
4. Package manager

✅ Correct Answer: 2

Does Rust guarantee Tail Call Optimization?

1. Depends on recursion
2. On using safe block
3. No
4. Yes

✅ Correct Answer: 3

In a function declaration, we can use &self, self and &mul. When is self used?

1. Value consumed by function
2. Read only reference to value needed
3. Value mutated by function
4. Refer to local variable

✅ Correct Answer: 1

When is unwrap() used in Rust?

1. For loop optimizations
2. To make code linear
3. Compiler optimizations
4. For debugging

✅ Correct Answer: 4

What is the version of the latest Rust release (As of late 2021)?

1. 1.31.1
2. 2.0.0
3. 1.55.0
4. 1.1.0

✅ Correct Answer: 3

Which company controls Rust Programming Language?

1. LLVM
2. Mozilla
3. Google
4. The Rust Foundation

✅ Correct Answer: 4

Is Rust an Object Oriented Programming (OOP) Language?

1. Yes, it is OOP
2. No, it is multi paradigm
3. No, it is Procedural
4. No, it is functional

✅ Correct Answer: 2

There are many string data types in Rust like Slice, OsStr, str, CStr, Owned, String, OsString and CString. Which one is a primitive data type in Rust?

1. Owned
2. CString
3. str
4. String

✅ Correct Answer: 3

Does Rust support "Move Constructors"

1. yes
2. Only for primitive data type
3. Yes, if Move() is implemented
4. No

✅ Correct Answer: 4

Is Rust Garbage Collected by default?

1. Only when pointers are used
2. Depends on memory usage
3. No
4. Yes

✅ Correct Answer: 3

How to disable warnings in Rust about unused code segments?

1. what_is_this()
2. std::any::type_name
3. variable.type_name()
4. std::intrinsic::type_name

✅ Correct Answer: 2

How to print data type of a variable in Rust?

1. what_is_this()
2. std::any::type_name
3. variable.type_name()
4. std::intrinsic::type_name

✅ Correct Answer: 2

How to convert a String to an Integer (int) in Rust?

1. my_string.parse()
2. int(my_string)
3. my_string.to_int()
4. my_string.parse().unwrap();

✅ Correct Answer: 4

There are 3 different ways to return an iterator in Rust: into_itr, itr and itr_mul. What is the yield of the returned iterator for itr?

1. &T
2. T
3. &mut T
4. mut T

✅ Correct Answer: 1

Rust supports many tools officially like Rustup and Rustfmt. What is Clippy tool in Rust?

1. Code cleanup
2. Linter
3. Code formatter
4. Code compressor

✅ Correct Answer: 2

What will be the output of the above Rust code?

1. 54
2. 66
3. Compilation error
4. Runtime error

✅ Correct Answer: 1

The above code outputs the size of variable a. What is the output (in bytes)?

1. 4
2. 2
3. o
4. 1

✅ Correct Answer: 3

What is the output of the above code?

1. 32
2. undefined
3. 44
4. 21

✅ Correct Answer: 3

From previous question, we know increment and decrement operators does not exist in Rust. What will be the output of the above code?

1. 2
2. option3
3. option2
4. option4

✅ Correct Answer: 1

Which function in Rust helps to clean heap memory?

1. flush
2. deallocate
3. clean
4. Drop

✅ Correct Answer: 4

From which code does the compilation of a Rust project begin

1. cargo root
2. carte root
3. root
4. root use

✅ Correct Answer: 2

In a Rust code, what does & denote in a function signature?

1. Reference of parameter
2. type of parameter
3. Pointer of parameter
4. Address of parameter

✅ Correct Answer: 2

In Rust, which keyword is used to define a boolean?

1. bool
2. Boolean
3. boolean
4. :boolean

✅ Correct Answer: 1

What bracket is used as a placeholder in Rust?

1. ()
2. {}
3. []
4. ::()::

✅ Correct Answer: 2

Which is the following is a correct Rust syntax?

1. let slice = &s[0..5];
2. let slice = s[0->5];
3. let slice = &s[0->5];
4. let slice = s[0..5];

✅ Correct Answer: 1