TypeScript Online Test

A gaming company is working on a platformer game. They need a method that will compute the character's final speed, given a map and a starting speed.

The terrain on which the game character moves forward is made from various pieces of land placed together. Implement the method calculateFinalSpeed which takes the initial speed of the character, and an array of degrees of inclination that represent the uneven terrain.

The speed of the character will increase or decrease proportionally to the incline of the land, as shown in the image below:

The magnitude of the angle of inclination will always be < 90°. The speed change occurs only once for each piece of land. The method should immediately return 0 as the final speed if an incline reduces the speed to 0 or below 0, which makes the character lose 1 life.

For example, the below code:

console.log(calculateFinalSpeed(60, [0, 30, 0, -45, 0]));

should print:

75

Your company is analyzing malware which targets numerical record files.

The malware uses a sliding window over the array of numbers in a file, and tries to match the following pattern:

Tl, -, -, X, -, -, -, Tr

The entire window is moved so that 'X' passes through all the values and is compared to the numbers at the 'Tl' and 'Tr' locations, which are positioned at a constant offset to 'X'.

The malware has the following rules:

• If the value at the 'Tl' or 'Tr' position of the pattern is bigger or equal to the value at the 'X’ position, the malware replaces the value at 'X' with 0.
• If the value at the 'Tl' or 'Tr' offset is out of bounds, then the value at 'X' is only compared to the other existing value.
• The record is processed in two stages: first, all the positions that should be set to 0 are located, using the original values for comparison. Only after all positions have been identified do they get set to 0.

For example, if the values in a record file are the following:

[1, 2, 0, 5, 0, 2, 4, 3, 3, 3]

The expected values after the malware runs are:

[1, 0, 0, 5, 0, 0, 0, 3, 3, 0]

In this example, both '2's, the '4' and the last '3' were replaced by 0.

Implement the simulate function so that the malware behavior is replicated for further study.

A megastore offers three types of discounts, which are represented as DiscountType enum.

Implement the getDiscountedPrice method which should take the total weight of the shopping cart, the total price, and the discount type. It should return the final discounted price based on the discount schemes as shown in the promotional video below:

(Open full-size video in a new tab)

For example, the following code:

console.log(getDiscountedPrice(12, 100, DiscountType.Weight));

should print:

82

A turn-based strategy game has a grid with water and land. The grid contains a true value where it's water and false where it's land.

The player controls a boat unit with a particular movement pattern. It can only move to fixed destinations from its current position as shown in the image below:

The boat can only move in a direct path through water to the possible destinations, so a destination will become unreachable if there is land in the way. 

Implement the canTravelTo function, that checks whether a destination is reachable by the boat. It should return true for destinations that are reachable according to the pattern above, and false for unreachable or out of bounds destinations which are outside the grid. 

For example, consider the following code:

const gameMatrix = [
  [false, true,  true,  false, false, false],
  [true,  true,  true,  false, false, false],
  [true,  true,  true,  true,  true,  true],
  [false, true,  true,  false, true,  true],
  [false, true,  true,  true,  false, true],
  [false, false, false, false, false, false],
];

console.log(canTravelTo(gameMatrix, 3, 2, 2, 2)); // true, Valid move
console.log(canTravelTo(gameMatrix, 3, 2, 3, 4)); // false, Can't travel through land
console.log(canTravelTo(gameMatrix, 3, 2, 6, 2)); // false, Out of bounds

The following image shows valid and invalid destinations when the boat is in the position (3, 2):

The Circle class is used in a prototype for a game engine. Finish the class so that:

• It inherits from the GameObject class
• It has one more public field, radius
• It has only one constructor, that sets the radius, and sets the x and y fields using the GameObject class

For example, executing the following code:

let circle = new Circle(10, 50, 8);
console.log(circle.x, circle.y, circle.radius);

should print "10 50 8".

Extend the Permission enum so that it has the following fields:

• Read, which should have a value of 1
• Write, which should have a value of 2
• Execute, which should have a value of 4

Extend the getPermissionList function so that it accepts a combination of several Permission enums and returns an array of strings which are the names of the Permissions.

For example, executing:

getPermissionList(Permission.Read | Permission.Write);

should return [ 'Read', 'Write' ] in any order.

Your company assigns each customer a membership ID, and you are implementing a check digit for those IDs.

The check digit should be calculated by adding up all digits in each membership ID. If the result of the sum is a number with more than a single digit, another iteration is required, and the digits of the result should also be added together. This process should repeat until a single-digit number is calculated.

For example, for the membership ID "55555" the sum of all digits is 25. Because this is not a single-digit number, 2 and 5 would be added, and the result, 7, would be the check digit.

You are working on a calculator application where users can input a mathematical expression such as: (3 + 5) * (2 - 4).

To correctly evaluate this expression, the application needs to validate the expression and ensure that the parentheses are balanced. The balanced parentheses are crucial for determining the order of operations and evaluating the expression correctly.

You have used an AI assistant to generate the following function to check if the parentheses in an expression are balanced:

function isBalanced(parentheses: string): boolean {
    const stack: Array<String> = [];
    const opening: Set<String> = new Set(['(', '[', '{']);
    const closing: Set<String> = new Set([')', ']', '}']);
    const pairs: Record<string, string> = {
        ')': '(',
        ']': '[',
        '}': '{'
    };

    for (const c of parentheses) {
        if (opening.has(c)) {
            stack.push(c);
        } else if (closing.has(c)) {
            if (stack.length === 0 || stack[stack.length - 1] !== pairs[c]) {
                return false;
            }
            stack.pop();
        }
    }

    return stack.length === 0;
}

What is correct for the given function?

The following code initializes strings as three different types and attempts to make them uppercase. Which statements about the behavior of the typescript compiler are correct?

let stringType: string = "string type";
stringType.toUpperCase();

let anyType: any = "any type";
anyType.toUpper();
anyType.toUpperCase();

let objectType: Object = "object type";
objectType.toUpperCase();

Consider the following code:

class Positionable {
  locationX: number = 0;
  locationY: number = 0;
  moveTo(toX: number, toY: number) {
    this.locationX = toX;
    this.locationY = toY;
  }
}

class Rotatable {
  orientation: number = 0;
  rotate(orientation: number) {
    this.orientation += orientation;
  }
}

class MovingObject {
  locationX: number = 0;
  locationY: number = 0;
  orientation: number = 0;
  printPosition(){
    console.log(this.locationX, this.locationY);
  }
}

function applyMixins(derivedCtor: any, baseCtors: any[]) {
  baseCtors.forEach(baseCtor => {
    Object.getOwnPropertyNames(baseCtor.prototype).forEach(name => {
      derivedCtor.prototype[name] = baseCtor.prototype[name];
    });
  });
}

applyMixins(MovingObject, [Positionable, Rotatable]);
let mover = new MovingObject();

Select the statements that are correct.

The following code initializes three types representing the colors: red, green and blue.

type ColorType = [string, number, number, number];
let red: ColorType = ['Red', 1, 0, 0];
let green: [string, number, number, number] = ['Green', 0, 1, 0];
let blue = ['Blue', 0, 0, 1];

Select the statements that are correct.