Done coursework/sprint-2

Author: Seti-Jemal

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

@@ -1,5 +1,7 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The program will give an error.The error happens because `str`is written twice inside the function.
+
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -10,4 +12,14 @@ function capitalise(str) {
 }
 
 // =============> write your explanation here
+// The function already has an input called `str`
+// Inside the function, the code tries to create another variable called `str`using `let`
+//JavaScript does not allow the same varible name to be created again in same place.
+//Because of this, the program throwns an error.
+
 // =============> write your new code here
+
+function captialise(str){
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}

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

@@ -3,6 +3,9 @@
 // Why will an error occur when this program runs?
 // =============> write your prediction here
 
+// The program will give an error because of the `decimalNumber` is used outside the function.
+// Even though it is only created inside the function.
+
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
@@ -16,5 +19,15 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+//The variable `decimalNumber`is only insdie the function.
+// At the end of the program, console.log( decimalNumber) tries to print it ,
+// however, JavaScript cannot find that varible outside the function.
+// Because of this, the program throws an error.
+
 // 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

@@ -1,20 +1,29 @@
 
 // Predict and explain first BEFORE you run any code...
+// The program will give a SyntazError because a number (3) is used as peramter name in the function.
 
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// My perdiction is that program will not run and show a SyntaxError because 3 is not a valid variable name.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// Funtion parameters must be variable names.
+// You cannot use a number like 3 as name of parameter.
+//Javascript required a valid varible name inside the parentheses.
 
 // 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
+// The program will print 320 first.
+// Then it will " The result of mutiplying 10 and 32 is undefined".
+
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +12,15 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// The function multiply is used console.log(a * b) to show the result
+// however, it does not resturn the value .
+// when the function is used inside the sentence with ${multiply(10, 32)} 
+// JavaScript expects the function to give back a value.
+//Becuse the function does not return anything, the result becomes 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 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+//My perdiction the code will show "undefined" becuse the function does not return the sum numbers.
 
 function sum(a, b) {
   return;
@@ -9,5 +10,12 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// The return statemment is ematy and the "c=b" is written after return.
+//When JavaScript see return it stops the function, so a+b is never used.
+
 // 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
+//The code will always show 3 as the last digit because the function does not use the number inside getLastDigit().
 
 const num = 103;
 
@@ -15,10 +15,24 @@ 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 does not take any input parameter, it always uses the global variavle num = 103.
+// Because of this the last digit returend is always 3, regardless of the number passed in the function call.
+
 // 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 $(getlastDigita(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 was fixed by adding a parameter so it can return the last digit of the given number.

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 the BMI of someone based off their weight and height
+}
+
+function calculateBMI(weight, height) {
+  const bmi = weight / (height * height);
+  return Number(bmi.toFixed(1));
+}

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

@@ -14,3 +14,7 @@
 // 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 convertToUpperSnakeCase(str) {
+  return str.toUpperCase().trim().split("").join("_");
+}

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

@@ -4,3 +4,8 @@
 // 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(kilograms) {
+  const pounds = kilograms * 2.20462;
+  return Number(pounds.toFixed(2));
+}

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

@@ -18,17 +18,21 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// Pad wil be called 3 times because the return statement uses pad for hours, mintues and seconds.
 
 // 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
+// The value is 0 because totalHours is 0 when the input is 61 seconds.
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// The return value is "00" because padStart makes the number two digits by adding a 0 at the start.
 
 // 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
-
+// The value is 1 because the last call to pad uses remainingSeconds, which is 1 when the input is 61.
 // 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
+// The return value is "01" because padStart adds a 0 infornt of the single digit number.