London | 26-ITP-Sep | Anita Amirhaeri | Sprint 3 | coursework/sprint 3

Sprint-3/1-key-errors/0.js

@@ -1,13 +1,22 @@
 // Predict and explain first...
-//  =============> write your prediction here
-
+//  =============> We will have syntax error because string is the parameter of the function and the next line,it is declared wit let
+//so it is declared two times in one part
 // call the function capitalise with a string input
+
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+console.log(capitalise("mother"));
 // 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;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// =============> write your explanation here     SyntaxError: Identifier 'str' has already been declared
+// =============> write your new code here.
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}

Sprint-3/1-key-errors/1.js

@@ -1,7 +1,9 @@
-// Predict and explain first...
+// Predict and explain first...:It doesn't run.We have a syntaxError.
 
-// Why will an error occur when this program runs?
-// =============> write your prediction here
+// Why will an error occur when this program runs?because decimalNumber is declared.
+// as a parameter and then declared again using const.
+
+// =============> write your prediction here:We will have a SyntaxError because decimalNumber is  a parameter of the function, but it is declared again using const inside the function.
 
 // Try playing computer with the example to work out what is going on
 
@@ -14,7 +16,14 @@ function convertToPercentage(decimalNumber) {
 
 console.log(decimalNumber);
 
-// =============> write your explanation here
+// =============> write your explanation here:decimalNumber is inside the function, so we can not use it outside the function.
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+ ca
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));

Sprint-3/1-key-errors/2.js

@@ -3,18 +3,23 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// =============> write your prediction of the error here:We will have a SyntaxError because we need a valid function parameter. 
 
 function square(3) {
     return num * num;
 }
 
-// =============> write the error message here
+// =============> write the error message here:SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// =============> explain this error message here:function square(3) {
+//3 is a number, not a valid variable. Program expects a parameter name there.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// =============> write your new code here:
+function square(num) {
+    return num * num;
+}
 
+console.log(square(3));
 

Sprint-3/2-mandatory-debug/0.js

@@ -1,14 +1,22 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// =============> write your prediction here:
+//The code will run, but the output won't be what we expect because the multiply function logs the result instead of returning it.
 
 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
-
+// =============> write your explanation here:console.log(a * b);
+//The result is 320, but the function doesn't return a value. It shows us undefined because we don't have return in the function.
+//320
+//The result of multiplying 10 and 32 is undefined
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+//  =============> 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-3/2-mandatory-debug/1.js

@@ -1,5 +1,6 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> write your prediction here:This is the error:The sum of 10 and 32 is undefined.
+// The code will run without a syntax error, but it will return undefined instead of 42.
 
 function sum(a, b) {
   return;
@@ -8,6 +9,15 @@ function sum(a, b) {
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// =============> write your explanation here:
+//The problem is that return; immediately ends the function://return;
+//a + b;
+
+//if we write anything after return(next line)is unreachable, so a + b doesn't run. The function therefore returns 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-3/2-mandatory-debug/2.js

@@ -1,7 +1,7 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// =============> Write your prediction here:I predict the output will be 3 every time, because the function uses the global constant num = 103 instead of using the numbers passed into getLastDigit().
 
 const num = 103;
 
@@ -14,11 +14,28 @@ 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
+// =============> 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
+// =============> write your explanation here:there is no parameter in the function.
+//So when we call the function:
+//getLastDigit(42)
+//the 42 is passed to the function, but the function has no parameter to receive it.
+//Instead, it uses the global variable (const num = 103)
+//so every call converts 103 to a string and gets its last digit: 3.
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// =============> 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)}`);
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem

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

@@ -15,5 +15,7 @@
 // It should return a string of 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);
 }
+// return the BMI of someone based off their weight and height

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

Sprint-3/3-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("250p"));
+console.log(toPounds("99p"));
+console.log(toPounds("5p"));

Sprint-3/4-mandatory-interpret/time-format.js

@@ -21,18 +21,41 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// =============> write your answer here: three calls to pad() in the return statement:
+//return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
 
 // 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
+// =============> write your answer here:
+//For formatTimeDisplay(61):
+//remainingSeconds = 61 % 60 = 1
+//totalMinutes = (61 - 1) / 60 → 1
+//remainingMinutes = 1 % 60 → 1
+//totalHours = (1 - 1) / 60 → 0
+//num = 1
 
 // c) What is the return value of pad when it is called for the first time?
-// =============> write your answer here
+// =============> write your answer here:num is 0.
+//let numString = num.toString(); gives us 0
+
+// This loop adds a "0" because the string has only one character:
+//numString = "0" + "0";
+//return value is:
+//"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
+// =============> write your answer here:
+//The last call is:   pad(remainingSeconds)
+
+//For 61 seconds, remainingSeconds is 61 % 60 = 1:
+//so num = 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
+// =============> write your answer here:
+//num is 1, so:
+//num.toString() gives "1".
+
+// and this loop adds a 0 to the beginning: "01"
+
+//So the final result of formatTimeDisplay(61) is: 00:01:01