The Calculator

• Write a function called squareNumber that will take one argument (a number), square that number, and return the result. It should also log a string like "The result of squaring the number 3 is 9."
• Write a function called halfNumber that will take one argument (a number), divide it by 2, and return the result. It should also log a string like "Half of 5 is 2.5.".
• Write a function called percentOf that will take two numbers, figure out what percent the first number represents of the second number, and return the result. It should also log a string like "2 is 50% of 4."
• Write a function called areaOfCircle that will take one argument (the radius), calculate the area based on that, and return the result. It should also log a string like "The area for a circle with radius 2 is 12.566370614359172."
  • Bonus: Round the result so there are only two digits after the decimal.
• Write a function that will take one argument (a number) and perform the following operations, using the functions you wrote earlier1:
  1. Take half of the number and store the result.
  2. Square the result of #1 and store that result.
  3. Calculate the area of a circle with the result of #2 as the radius.
  4. Calculate what percentage that area is of the squared result (#3).

See Solution

function squareNumber(num) {
    var squaredNumber = num * num;
    console.log('The result of squaring the number ' + num + ' is ' + squaredNumber);
    return squaredNumber;
}

squareNumber(3);

function halfOf(num) {
    var half = num / 2;
    console.log('Half of ' + num + ' is ' +  half);
    return half;
}

halfOf(5);

function percentOf(num1, num2) {
    var percent = (num1/num2) * 100;
    console.log(num1 + ' is ' + percent + '% of ' + num2);
    return percent;
}

percentOf(5, 10);

function areaOfCircle(radius) {
    var area = Math.PI * squareNumber(radius);
    console.log('The area of circle with radius ' + radius + ' is ' + area);
    return area;
}

areaOfCircle(2);

function doCrazyStuff(num) {
    var half    = halfOf(num);
    var squared = squareNumber(half);
    var area    = areaOfCircle(squared);
    var result  = percentOf(squared, area);
}

doCrazyStuff(5);