Glasgow | Jan-26 | Elisabeth Matulian | Sprint 2 | Coursework

Sprint-2/1-key-errors/0.js

@@ -9,5 +9,10 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
+// =============> write your explanation here 
+// It leeds to an error declaring the same variable name more than 1 time.
+// It also can confuse reassigning the variable str. it is better to remove it or made up a new one.  
 // =============> write your new code here
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}

Sprint-2/1-key-errors/1.js

@@ -1,8 +1,8 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
-
+// decimalNumber was already declared on the line 8. it leads to an error declaring it the second time on the line 9. 
+// line 15 is in global scope and tries output value of the local variable from inside of the function. 
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
@@ -14,7 +14,13 @@ function convertToPercentage(decimalNumber) {
 
 console.log(decimalNumber);
 
-// =============> write your explanation here
+// i will declare the decimalNumber variable before the function and call the function. i would also removed the percentage variable because it doesn't make anything useful in this piece of code. 
 
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+const decimalNumber = 0.5;
+function convertToPercentage(decimalNumber) {
+  return `${decimalNumber * 100}%`;
+}
+
+console.log(convertToPercentage(decimalNumber))
+

Sprint-2/1-key-errors/2.js

@@ -4,17 +4,22 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+//reference error (not existing variable (num))
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
+//When we declare a function, it is expected that the parameter names will be in brackets. 
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
-
+function square(num) {
+    return num * num;
+}
 

Sprint-2/2-mandatory-debug/0.js

@@ -1,6 +1,7 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// missed "return". undefined output. 
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +10,12 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+//return — returns a value from a function to the outside 
 
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);

Sprint-2/2-mandatory-debug/1.js

@@ -1,5 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// invalid syntax
 
 function sum(a, b) {
   return;
@@ -9,5 +10,11 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+//if the code does not return anything, then the output is undefined
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);

Sprint-2/2-mandatory-debug/2.js

@@ -2,6 +2,7 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// the output is always going to be '3'
 
 const num = 103;
 
@@ -15,10 +16,21 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+//The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
 // Explain why the output is the way it is
 // =============> write your explanation here
+// when the function is declared there is no parameters so in the body of function, num refers to global variable which has always the same value, so when we call the function arguments are ignored.  
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem

Sprint-2/3-mandatory-implement/1-bmi.js

@@ -15,5 +15,7 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
+    return Number((weight / (height * height)).toFixed(1))
+}
+
+console.log(calculateBMI(120 , 1.85))

Sprint-2/3-mandatory-implement/2-cases.js

@@ -14,3 +14,9 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+
+function upperSnakeCase(str) {
+    return str.toUpperCase().replaceAll(" ","_");
+}
+
+console.log(upperSnakeCase("Use the MDN string documentation to help you find a solution"))

Sprint-2/3-mandatory-implement/3-to-pounds.js

@@ -4,3 +4,18 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+
+function toPounds(penceString) {
+    const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1)
+    const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); //399
+    const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+    const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+    return `£${pounds}.${pence}`;
+}
+
+console.log(toPounds("399p"))
+console.log(toPounds("3999p"))
+console.log(toPounds("99p"))
+console.log(toPounds("9p"))
+
+

Sprint-2/4-mandatory-interpret/time-format.js

@@ -11,24 +11,25 @@ function formatTimeDisplay(seconds) {
   return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
 }
 
+
 // You will need to play computer with this example - use the Python Visualiser https://pythontutor.com/visualize.html#mode=edit
 // to help you answer these questions
 
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// =============> 3 times
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
 // b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
+// =============> 0
 
 // c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// =============> "00"
 
 // d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// =============> 1. The remainder operator (%) returns the remainder left after dividing one number by another number. 61 % 60
 
 // e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// =============> 01. The padStart() method takes the length of the string as its first value, and the second value is what will fill the beginning of the string if its length is insufficient. 

Sprint-2/5-stretch-extend/format-time.js

@@ -4,8 +4,15 @@
 
 function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
+  const mins = time.slice(-2);
   if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+    return `${(hours - 12).toString().padStart(2, '0')}:${mins} pm`; 
+  }
+  else if (hours == 0) {
+    return `12:${mins} am`;
+  }
+  else if (hours == 12) {
+    return `${time} pm`;
   }
   return `${time} am`;
 }
@@ -23,3 +30,31 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+const currentOutput3 = formatAs12HourClock("23:59");
+const targetOutput3 = "11:59 pm";
+console.assert(
+  currentOutput3 === targetOutput3,
+  `current output: ${currentOutput3}, target output: ${targetOutput3}`
+);
+
+const currentOutput4 = formatAs12HourClock("00:00");
+const targetOutput4 = "12:00 am";
+console.assert(
+  currentOutput4 === targetOutput4,
+  `current output: ${currentOutput4}, target output: ${targetOutput4}`
+);
+
+const currentOutput5 = formatAs12HourClock("12:00");
+const targetOutput5 = "12:00 pm";
+console.assert(
+  currentOutput5 === targetOutput5,
+  `current output: ${currentOutput5}, target output: ${targetOutput5}`
+);
+
+const currentOutput6 = formatAs12HourClock("13:00");
+const targetOutput6 = "01:00 pm";
+console.assert(
+  currentOutput6 === targetOutput6,
+  `current output: ${currentOutput6}, target output: ${targetOutput6}`
+);