Rust-String

Question 1

Classifications of the String data type

Answer 1

String literal(&str)
String Object(String)

Question 2

When is the String literal used?

Answer 2

String literals are used when the value of a string is know at compile time.

String literals are a set of characters, which are hardcoded into a variable.

String literals are also known as string slices

Question 3

Give an example of a string literal declaration

Answer 3

let company:&str = “TutorialsPoint”;
let first_name:&str = “Prince”;

Question 4

Describe String object

Answer 4

The String object type can be used to represent string values that are provided at runtime

Question 5

Where is the string object allocated?

Answer 5

Heap

Question 6

How do create an empty string object

Answer 6

String::new();

Question 7

Give an example of a program using the string object

Answer 7

fn main(){
let empty_string = String::new();
println!(“length is {}”,empty_string.len());

let content_string = String::from(“TutorialsPoint”);
println!(“length is {}”,content_string.len());
}

Question 8

Mention common methods of the string object

Answer 8

new()
to_string()
replace()
push()
push_str()
len()
trim()
split_whitespace()
split()
chars()

Question 9

Describe the to_string()

Answer 9

Converts the given value to a String.

Question 10

Describe replace()

Answer 10

Replaces all matches of a pattern with another string.

Question 11

Describe push() and push_str()

Answer 11

push() - Appends the given char to the end of this String.

push_str() - Appends a given string slice onto the end of this String.

Question 12

Describe split() and chars()

Answer 12

split() –Returns an iterator over substrings of this string slice, separated by characters matched by a pattern.

chars() – Returns an iterator over the chars of a string slice.

Question 13

Give an example of the string object with using at least two of its method

Answer 13

fn main(){
let mut z = String::new();
z.push_str(“hello”);
println!(“{}”,z);
}

Question 15

You can convert a string literal to a string object how

Answer 15

let name = “Prince”.to_string();

Question 16

How do you use the replace() method;

Answer 16

let sentence = “Ibekwe is 19”;
sentence.to_string();
let sentence2 = sentence.to_replace(“Ibekwe”,”Prince”)

Question 17

Give an example on how to use split_whitespace();

Answer 17

fn main(){
let msg = “Tutorials Point has good tutorials”.to_string();
let mut i = 1;

for token in msg.split_whitespace(){
println!(“token {} {}”,i,token);
i+=1;
}
}

//token 1 Tutorials
//token 2 Point
//token 3 has
//token 4 good
//token 5 tutorials