answered the exercises of the key errors and debug the mandatory file

Author: Ebrahim-Moqbel

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

@@ -1,13 +1,29 @@
 // Predict and explain first...
 //  =============> write your prediction here
+//function capitalize will capitalise the first letter with index 0 
+// and will append the sliced string from index 1 which is the second letter
 
 // call the function capitalise with a string input
+
 // interpret the error message and figure out why an error is occurring
+//syntax Error :identifier the variabel has already been declared. 
+// As we can see the str variable has already been declared in the prameter of the function instead we just return the value 
+// The Error message is 
 
-function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
-  return str;
-}
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   console.log(str);
+//   return str;
+// }
+
+
+// =============> write your explanation here 
 
-// =============> write your explanation here
 // =============> write your new code here
+
+function capitalise(str) {
+return `${str[0].toUpperCase()}${str.slice(1)}`;
+
+}
+capitalise("ebrahim");
+capitalise('salomi');

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

@@ -1,20 +1,35 @@
 // Predict and explain first...
 
+
 // Why will an error occur when this program runs?
 // =============> write your prediction here
 
+//1- The function is trying to declare the decimalNumber twice in the perameter and later as a new variable 
+//2-console.log() is printing a variable in the local scope where it can't be accessed as it is inside the function 
+
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
+
+//   return percentage;
+// }
 
-  return percentage;
-}
 
-console.log(decimalNumber);
 
-// =============> write your explanation here
 
+// =============> write your explanation here
+//similar to the previous exercise where the variable decimal Number has already been declared in the parameter 
+// and already is a local variable which can't be declared again  
+//As the decimalNumber inside the function we can't print it using the console.log() as it has no power to the local scope
+//instead we can delete the second declaration and just leave the parameter as an input for the user which would be nicely work
 // 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

@@ -4,16 +4,22 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+//The error might be accuring because the parameter can't be a number and should be a variable 
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
+//the Error is a syntax error: Unexpected number 
 
 // =============> explain this error message here
+// we can put a number or any argument when we call the number not when we shape it 
 
 // Finally, correct the code to fix the problem
+function square(num) {
+    return num * num;
+ }
 
 // =============> write your new code here
 

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

@@ -1,14 +1,23 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// This function would multiply the two arguments a and b whatever that is
+// when we log the output we will get the string and the output of the function but because we are not returning an output we might run into an error 
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// function multiply(a, b) {
+//   console.log(a * b);
+// }
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+//The console.log() inside the funtion will print a*b but when we call the function will return() undefined means will return nothing)for the two variables a and b
 
 // 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

@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The function suppose to return the sum of the two variables but we will encounter an error probably a syntax Error
 
-function sum(a, b) {
-  return;
-  a + b;
-}
-
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
+// function sum(a, b) {
+//   return;
+//   a + b;
+// }
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// As we return nothing by closing the line with a semicolon hence a + b is not returned where we tell the computer to exit and go back to global scope and the computer will not be able to read the lines after that
 // =============> write your explanation here
+
 // 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

@@ -2,23 +2,41 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+//getLastDigit will convert a number to a string and reverse it 
+// However, since there is no parameter or local variable we might run into an Error 
 
-const num = 103;
+// const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
-}
+// function getLastDigit() {
+//   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)}`);
+// 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 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
+// As expected, the function has no parameters, so it relies on the global variable "num" as its only variable.
+// Since there are no parameters defined, the function permanently uses the global variable instead.
+// This means even if we pass arguments when calling the function, they will be ignored because there are no parameters to receive them.
+
 // 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 +15,10 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
+    let result = weight / (height*height);
+    return result.toFixed(1);
+    
     // return the BMI of someone based off their weight and height
-}
+}
+
+console.log(calculateBMI(70,168))