Complete sprint 2 tasks

Author: serveyano

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

@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//A) Error message - str has already been declared
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
-  return str;
+  let capitalisedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalisedStr;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+console.log(capitalise("hello there"));

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

@@ -1,7 +1,9 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+
+// The error happens because decimalNumber is declared twice.
+
 
 // Try playing computer with the example to work out what is going on
 
@@ -16,5 +18,17 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+//// The error happens because decimalNumber is already a parameter,
+// so it cannot be declared again using const.
+// Also, decimalNumber is inside the function, so it can't be
+// used outside the function with console.log().
+
 // 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));

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

@@ -1,6 +1,9 @@
 
 // Predict and explain first BEFORE you run any code...
 
+// I think the code will give an error because 3 cannot be used
+// as a function parameter name. Parameters must be variable names.
+
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
@@ -11,10 +14,20 @@ function square(3) {
 
 // =============> write the error message here
 
+// SyntaxError: Unexpected number
+
 // =============> explain this error message here
+// The error means JavaScript found a number where it was
+// expecting a parameter name. Function parameters must be
+// identifiers like 'num', not values like 3.
 
 // 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

@@ -1,6 +1,9 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// I think the code will not give an error, but it will print
+// "The result of multiplying 10 and 32 is undefined" because
+// the function only logs the answer and does not return a value.
+
 
 function multiply(a, b) {
   console.log(a * b);
@@ -10,5 +13,14 @@ console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
 
+// The problem is that the multiply function uses console.log()
+// instead of returning the result. When a function does not
+// return anything, JavaScript gives it the value undefined.
+
 // 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 +1,10 @@
 // Predict and explain first...
-//  =============> write your prediction here
+
+// I think the code will not give an error, but it will print
+// "The sum of 10 and 32 is undefined" because the return statement
+// stops the function before a + b can run.
+
+
 
 function sum(a, b) {
   return;
@@ -9,5 +14,15 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+
+// The problem is that `return;` ends the function immediately.
+// The code after return will never be reached, so the function
+// does not return the sum of a and b. It returns undefined instead.
+
 // 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 +1,9 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// I think the output will be wrong because the function does not use
+// the numbers passed into it. It always uses the const num = 103,
+// so it will always return 3.
 
 const num = 103;
 
@@ -14,11 +16,31 @@ 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
+// 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
+
+// The function is not working properly because it does not have a
+// parameter to receive the numbers. It uses the global variable num,
+// which is always 103, so it always returns the last digit of 103.
+
+
 // 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
+
+// The function is not working properly because it does not use the
+// number that is passed into it. It uses the global variable `num`,
+// which is always 103, so it always returns 3.
+// The function needs a parameter so it can use each number given to it.

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

@@ -15,5 +15,8 @@
 // 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
-}
+  const bmi = weight / (height * height);
+    return bmi.toFixed(1);
+}
+
+console.log(calculateBMI(70, 1.73));

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

@@ -14,3 +14,10 @@
 // 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(text) {
+    return text.toUpperCase().replaceAll(" ", "_");
+}
+
+console.log(toUpperSnakeCase("hello there"));
+console.log(toUpperSnakeCase("lord of the rings"));

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

@@ -4,3 +4,27 @@
 // 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("399p"));
+console.log(toPounds("45p"));
+console.log(toPounds("5p"));
+console.log(toPounds("1234p"));

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

@@ -21,18 +21,21 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// pad will be called 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 modulo  % operator means that 61 gives a remainder of 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
+// "01"
+
+// pad adds a leading 0 to single-digit numbers, so 1 becomes "01".