A vector is a resizable collection that stores items of the same type. Its values are stored next to each other in memory. The vec! macro can be used to initialize a vector.
// Create a vector of numbers
let v1 = vec![3, 5, 8, 10, 12, 9];
// Create a vector of strings
let v2 = vec!["one", "two", "three"];
Below is an example of creating an empty vector and adding values to it.
// Add elements to an empty vector
let mut v3 = Vec::new();
v3.push(1.5);
v3.push(3.0);
v3.push(8.2);
println!("v3 is {:?}", v3);
// This prints:
// v3 is [1.5, 3.0, 8.2]
Use indexing to get values from a vector. Notice the first element is at index zero.
// Read elements from a vector
let v4 = vec![22, 38, 42, 50];
let first = &v4[0];
let third = v4[2];
let last = v4.last().unwrap();
println!("v4 is {:?}", v4);
println!("first is {}", first);
println!("third is {}", third);
println!("last is {}", last);
// This prints:
// v4 is [22, 38, 42, 50]
// first is 22
// third is 42
// last is 50
Use of for loop to iterate over the values in a vector.
// Iterate over elements in a vector
let v5 = vec![3, 4, 5, 6, 8, 12];
for v in v5 {
println!("v in v5 is {}", v);
}
// This prints:
// v in v5 is 3
// v in v5 is 4
// v in v5 is 5
// v in v5 is 6
// v in v5 is 8
// v in v5 is 12
// Iterate over elements in a vector by reference
let v5 = vec![3, 4, 5, 6, 8, 12];
for v in &v5 {
println!("v in v5 is {}", v);
}
// This prints the same as above.
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