Boolean Logic Exercises

Part I

Write down what the following statements will return. Try to figure this out before putting the commands in the chrome console.

1. 2 == "2";
2. 2 === 2;
3. 10 % 3;
4. 10 % 3 === 1;
5. true && false;
6. false || true;
7. true || false;

Part II

Answer the following questions about this code block:

(a)

let isLearning = true;
if(isLearning){
    console.log("Keep it up!");
} else {
    console.log("Pretty sure you are learning....");
}

1. What should the above code console.log?
2. Why do we not need to specify if(isLearning === true)? Why does if(isLearning) work on its own?

(b)

let firstvariable;
let secondvariable = "";
let thirdvariable = 1;
let secretMessage = "Shh!";

if(firstvariable){
    console.log("first");
} else if(firstvariable || secondvariable){
    console.log("second");
} else if(firstvariable || thirdvariable){
    console.log("third");
} else {
    console.log("fourth");
}

1. What should the above code console.log? Why?
2. What is the value of firstvariable when it is initialized?
3. Is the value of firstvariable a “truthy” value? Why?
4. Is the value of secondvariable a “truthy” value? Why?
5. Is the value of thirdvariable a “truthy” value? Why?

Part III

1. Research Math.random here and write an if statement that console.log’s “Over 0.5” if Math.random returns a number greater than 0.5. Otherwise console.log “Under 0.5”.
2. What is a falsey value? List all the falsey values in JavaScript.

Solutions

You can find the code here

When you’re ready, move on to Array Basics