Logical operators in Rust - Step-by-Step Execution

Concept Flow - Logical operators

Start

↓

Evaluate Left Operand

↓

Evaluate Right Operand

↓

Apply Logical Operator (&&, ||, !)

↓

Result: true or false

↓

Use Result in Condition or Expression

↓

End

Logical operators combine or invert boolean values to produce true or false results used in decisions.

Execution Sample

Rust

fn main() {
    let a = true;
    let b = false;
    let c = a && b;
    let d = a || b;
    let e = !a;
    println!("c: {}, d: {}, e: {}", c, d, e);
}

This code shows how &&, ||, and ! work with true and false values.

Execution Table

Step	Expression	Evaluation	Result
1	a = true	Assign true to a	a = true
2	b = false	Assign false to b	b = false
3	c = a && b	true && false	false
4	d = a || b	true || false	true
5	e = !a	!true	false
6	println!("c: {}, d: {}, e: {}", c, d, e)	Print values	c: false, d: true, e: false

💡 All expressions evaluated and printed; program ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	Final
a	uninitialized	true	true	true	true	true	true
b	uninitialized	uninitialized	false	false	false	false	false
c	uninitialized	uninitialized	uninitialized	false	false	false	false
d	uninitialized	uninitialized	uninitialized	uninitialized	true	true	true
e	uninitialized	uninitialized	uninitialized	uninitialized	uninitialized	false	false

Key Moments - 3 Insights

Why does 'a && b' result in false even though 'a' is true?

Because '&&' means both must be true. Since 'b' is false (see step 3 in execution_table), the whole expression is false.

What does the '!' operator do to 'a' in '!a'?

'!' flips the value. Since 'a' is true, '!a' becomes false (see step 5 in execution_table).

Why is 'a || b' true even though 'b' is false?

'||' means either one is true. Since 'a' is true, the whole expression is true (see step 4 in execution_table).

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the value of 'c'?

A true

B undefined

C false

D true && false

💡 Hint

Check the 'Result' column at step 3 in execution_table.

At which step does the variable 'e' get its value?

A Step 3

B Step 5

C Step 2

D Step 6

💡 Hint

Look for '!a' evaluation in execution_table.

If 'b' was true instead of false, what would be the value of 'c' at step 3?

A true

B false

C false && true

D undefined

💡 Hint

Recall that '&&' is true only if both sides are true (see step 3).

Concept Snapshot

Logical operators in Rust:
- && (AND): true if both true
- || (OR): true if one true
- ! (NOT): flips true/false
Used to combine or invert boolean values in conditions.

Full Transcript

This visual trace shows how Rust evaluates logical operators. Variables a and b are assigned true and false. Then c is a && b, which is false because b is false. d is a || b, true because a is true. e is !a, which flips true to false. The program prints these results. Logical operators combine or invert boolean values to decide true or false outcomes.