LESSON 181 OF 414 · PROJECTS: EVERYDAY PROGRAMS

Report Card V5 - Subject to Grade Dictionary in Rust

Practice

Use a dictionary, a loop, and conditionals to print each subject with its letter grade in alphabetical order.

You start with:

// Rust: the editor starts empty - declare the data yourself, for example:
let mut grades = BTreeMap::new();
grades.insert("Math", 92);
grades.insert("English", 78);
grades.insert("Science", 85);
grades.insert("History", 67);

Build:

English: C
History: D
Math: A
Science: B

Rules:

Visit the subjects in alphabetical order.
Look up each subject's score in the dictionary and apply the grading scale (90+ A, 80s B, 70s C, 60s D, else F).
On each iteration print the subject, a colon and a space, then the grade, for example English: C.

Use a BTreeMap<&str, i32> - it stores keys in sorted order.

let mut grades = BTreeMap::new();
grades.insert("Math", 92);
grades.insert("English", 78);
grades.insert("Science", 85);
grades.insert("History", 67);
for (subject, score) in &grades {
    let grade;
    if *score >= 90 {
        grade = "A";
    } else if *score >= 80 {
        grade = "B";
    } else if *score >= 70 {
        grade = "C";
    } else if *score >= 60 {
        grade = "D";
    } else {
        grade = "F";
    }
    println!("{}: {}", subject, grade);
}

STEP 1 OF 11

Guided

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Report Card V5 - Subject to Grade Dictionary in Rust

Report Card V5 in Rust