question01.js

// Fill inside of the optimizeFunction function
function doExpensiveTask(input) {
    const result = 2 * input
    console.log("Doing expensive task...:", result);
    return result;
}
function optimizeFunction(func) {
    /*
    * Only write code in this function.
    * This function returns an optimized version of the func
    */
   var cache = {};

    return function (k) {
        if (k in cache) {
            return console.log("Same input, no need to calculate: "+cache[k]);
        } else {
            cache = {};
            var val = func.apply(this, arguments);
            cache[k] = val;
            return val;
        }
    }
}
    // optimizedFunc shouldn't execute the expensive task if new input is same as the previous one
    const optimizedFunc = optimizeFunction(doExpensiveTask);
    optimizedFunc(2); // Should print: Doing expensive task...: 4
    optimizedFunc(2); // Should print: Same input, no need to calculate: 4
    optimizedFunc(4); // Should print: Doing expensive task...: 8
    optimizedFunc(4); // Should print: Same input, no need to calculate: 8
    optimizedFunc(2); // Should print ((Forgets the old one)): Doing expensive task...: 4

question02.js

/*
 * Fill inside of the makeFunctionWithFixedThis function
 * You can use console.log for debugging purposes
 * But, before submitting your answer you should remove any debug statements,
 * only console.log statement should be in the printName method
 */
class Person {
    constructor(firstName) {
        this.firstName = firstName
    }
    printName() {
        // This should be the only console.log statement in the submitted work
        console.log(this.firstName)
    }
}
const personA = new Person('AAA')
const personB = new Person('BBB')
// See that these statements doesn't print correct firstNames
setTimeout(personA.printName, 0)
setTimeout(personB.printName, 0)
function makeFunctionWithFixedThis(func, objToBeThis) {
    /*
    * only write code in this function
    * This function returns a function with fixed 'this'
    */
   return function () {
       func.apply(objToBeThis);
   }
}
const fixedPersonAPrint = makeFunctionWithFixedThis(personA.printName, personA)
const fixedPersonBPrint = makeFunctionWithFixedThis(personB.printName, personB)
// After implementing body of makeFunctionWithFixedThis,
// these setTimeout calls should print the firstNames correctly
setTimeout(fixedPersonAPrint, 0)
setTimeout(fixedPersonBPrint, 0)