London | 26-ITP-May | Khaliun Baatarkhuu | Sprint 2 | Coursework

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

@@ -1,5 +1,8 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> My prediction is the code will not work properly
+//due to "str" being a parameter on the first line, then it being declared
+//again on the second line as a variable, essentially creating two declarations
+// under one name, in the same scope. 
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -9,5 +12,36 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// =============> Uncaught SyntaxError: Identifier 'str' has already been declared - VM779:2
+//Above is the error message i got, when i ran the code in my chrome console. My prediction 
+// was correct, 'str' has been declared twice, and also the error is on line 2. 
+
+// =============> I shall erase 'let' keyword and see what happens.
+
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+
+//function works, called on it by adding 
+
+capitalise("cyf");
+
+//at the end.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+

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

@@ -1,20 +1,43 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============> just like in the previous exercise, you can't have two variables 
+//with the same name in one scope. Second error is you can't call on "decimalNumber"
+//from outside the function. Since that variable only lives inside the function.
 
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
+//a parameter (decimalNumber) is created
   const decimalNumber = 0.5;
+//this is where the first error appears, as now there are two clashing variables 
+//under the same name. Code stops working.  
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
 
 console.log(decimalNumber);
 
-// =============> write your explanation here
+// =============> my prediction was correct. 
 
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// =============> 
+
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));
+
+//removed the clashing variable and placed the function call inside the 
+//console log.
+
+
+
+
+
+
+
+

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

@@ -3,18 +3,25 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// =============> it won't work due to num variable not being set, also parameter can't be a number.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
 
+Uncaught SyntaxError: Unexpected number VM367:1
+
 // =============> explain this error message here
+//There is a syntax error on line 1 ie 3 acting as a parameter is wrong
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// =============> 
+function square(num) {
+    return num * num;
+}
 
+console.log(square(3));
 

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

@@ -1,14 +1,31 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// =============> this code needs a return function to insert 320 into the string  
 
 function multiply(a, b) {
   console.log(a * b);
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-// =============> write your explanation here
+// =============> this code creates a function called multiply on  line 5, line 6 is ignored for now because it's part of the function definition.
+//Then JS read the code further from top to bottom until line 9, where it sees the values attached to the parameters and runs the function on 5 now, with new values. 
+//lines 6 then becomes console.log(320). Function ends here. 
+
+//
 
 // 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)}`);
+
+/* 
+
+this exercise is about understanding the differemce between console and return , in essense. 
+With return, the value can be inserted into the template literal.
+With console.log, the value is only displayed and then discarded.
+
+*/

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

@@ -1,13 +1,20 @@
 // Predict and explain first...
-//  =============> write your prediction here
-
+//  =============> due to the semicolon on line 5 , the function will not progress further. In the console line template literal becomes 
+//`The sum of 10 and 32 is ${undefined}`
 function sum(a, b) {
   return;
   a + b;
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// =============> my prediction was correct, i have removed the semicolon and put the expression on line 6 with the return function on line 5.
+
 // 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

@@ -1,7 +1,7 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// =============> there is no paramater for getLastDigit to work with but a fixed value of 103 outside the function, so the console will show 3 everytime. 
 
 const num = 103;
 
@@ -14,11 +14,31 @@ console.log(`The last digit of 105 is ${getLastDigit(105)}`);
 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
+// =============> 
+VM447:7 The last digit of 42 is 3
+VM447:8 The last digit of 105 is 3
+VM447:9 The last digit of 806 is 3
+
+undefined
+
 // Explain why the output is the way it is
-// =============> write your explanation here
+// =============> because when the console.log calls for the function there are no parameters in it, so 42 gets ignored. 
+//However 103 is used because it is part of the return function under num keyword. Therefore causing the error for all the console lines.
+
+
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// =============> 
+const num = 103;
+
+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)}`);
+
+// Now, with getLastDigit having a num variable, function will be able to assign different digits when console calls on it. 
+
 
 // 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 +15,10 @@
 // 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(80, 1.76));
+
+25.8 
+//(I am officially overweight, :(

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

@@ -14,3 +14,12 @@
 // 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 toUpperSnakeCase(str) {
+  const upperCaseString = str.toUpperCase();
+  const snakeCaseString = upperCaseString.replaceAll(" ", "_");
+
+  return snakeCaseString;
+}
+
+console.log(toUpperSnakeCase("hello there"));

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

@@ -4,3 +4,28 @@
 // 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");
+
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+
+console.log(toPounds("666p"));
+console.log(toPounds("69p"));
+console.log(toPounds("13p"));
+console.log(toPounds("1000p"));

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

@@ -21,18 +21,20 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// =============> Pad's called three times, per hours, minutes and seconds each.
 
 // 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
+// =============> Answer is zero, due to 61 seconds being less than an hour.
 
 // c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// =============> The function returns 00, after running twice. 
 
 // 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
+// =============> When it runs for the last time it's calculating remaining seconds, with value of 61, after dedicting minutues the answer
+//is 1. 
 
 // e) What is the return value of pad when it is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// =============> Answer is 01, because numString convert 1 to "1", then loop runs again, now it's "01", because of "while (numString.length < 2) {
+// numString = "0" + numString;}" , then the loop stops. 

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

@@ -23,3 +23,64 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+// i am runnign the following tests, since morning and afternoon times were done already,
+// noon, different minutes.
+function formatAs12HourClock(time) {
+  const hours = Number(time.slice(0, 2));
+ /*  
+  Since we know what the bug is, i shall handle it as a special case, and add the following code.
+
+  if (hours === 12) {
+    return `${time} pm`;
+  }
+
+  Tested it again and it works now. 
+  */
+  if (hours > 12) {
+    return `${hours - 12}:00 pm`;
+  }
+  return `${time} am`;
+}
+
+const currentOutput3 = formatAs12HourClock("12:00");
+const targetOutput3 = "12:00 pm";
+console.assert(currentOutput3 === targetOutput3);
+
+console.log(formatAs12HourClock("12:00"));
+
+//i have run this code in dev tools , the asnwer was 12:00am , bug found. 
+
+
+
+function formatAs12HourClock(time) {
+  const hours = Number(time.slice(0, 2));
+  const minutes = time.slice(3);
+
+  if (hours === 12) {
+    return `${time} pm`;
+  }
+
+  if (hours > 12) {
+     return `${hours - 12}:${minutes} pm`;
+  }
+  return `${time} am`;
+}
+
+const currentOutput3 = formatAs12HourClock("12:00");
+const targetOutput3 = "12:00 pm";
+console.assert(currentOutput3 === targetOutput3);
+
+console.log(formatAs12HourClock("15:29"));
+
+//Answer was 3:00pm, bug found. 
+
+//PS: fixed the bug by adding a seperate variable for minutes. Tested it again and it works now. 
+
+
+
+
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+