Manchester | 26-ITP-JAN | Abdu Mussa | Sprint 1 | structuring and Testing Data

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,4 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+// line 3 is reassigning the value of the variable, = sign is used to reassign the value of count to increment by 1.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,6 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

Sprint-1/1-key-exercises/3-paths.js

@@ -16,8 +16,10 @@ console.log(`The base part of ${filePath} is ${base}`);
 
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
+const secondCharacterIndex = 1;
+const startingPointForExtension = filePath.lastIndexOf(".");
 
-const dir = ;
-const ext = ;
-
-// https://www.google.com/search?q=slice+mdn
+const dir = filePath.slice(secondCharacterIndex, lastSlashIndex);
+const ext = filePath.slice(startingPointForExtension + 1);
+console.log(`The dir part of ${filePath} is ${dir} and the ext part is ${ext}`);
+// https://www.google.com/search?q=slice+mdn

Sprint-1/1-key-exercises/4-random.js

@@ -1,9 +1,12 @@
-const minimum = 1;
-const maximum = 100;
-
+const [min, max] = [1, 100];
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
 // In this exercise, you will need to work out what num represents?
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+/*num represents a number in [1, 100] and Math.random() returns a number in [0, 1).
+Math.floor is a method that rounds a number down to the nearest whole number.
+first of all i will try to get a value [0, 1) from Math.random and multiple it by 100
+and apply Math.floor to the result which will give me the integer number and then add the minimum value i.e. 1  */

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

@@ -1,2 +1,4 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+/*This is just an instruction for the first activity - but it is just for human consumption
+We don't want the computer to run these 2 lines - how can we solve this problem? */
+
+/*when we try to write comment and instruction and we want the computer not to run it we can comment them using // for single line and /* for multiple lines. */

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

@@ -1,4 +1,5 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+// To reassign  a value of age we have to use let not const.

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

@@ -1,5 +1,7 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
-
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
+//the code try to log the variable before declaring the variable
+// if we declare and initialize the variable first then we can use it.

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

@@ -1,9 +1,12 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+/* the code is not working because of the variable type which is .slice method work on 
+string and array variable types not on number variable types to fix it we can change the variable type to 
+string variable type by adding double quotation marks to the variable.*/

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,4 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const hourClockTime12 = "20:53";
+const hourClockTime24 = "08:53";
+
+// Numbers are not allowed as the first character in naming of variables.

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -12,11 +12,26 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+/* there are 5 function calls in this code.
+    1) Number(carPrice.replaceAll(",","")); line 4.
+    2) Number(priceAfterOneYear.replace("," "")) line 5.
+    3) carPrice.replaceAll(",", "") line 4.
+    4) priceAfterOneYear.replaceAll("," "") line 5.
+    5) console.log(`The percentage change is ${percentageChange}`);  line 10. */ 
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+//the error is coming from line 5 and the error is missing between the arguments.
 
 // c) Identify all the lines that are variable reassignment statements
+/*on line 4- carPrice = Number(carPrice.replaceAll(",", ""));  
+  on line 5- priceAfterOneYear = Number(priceAfterOneYear.replaceAll(","), "")*/
 
 // d) Identify all the lines that are variable declarations
+/* line 1- let carPrice = "10,000";  
+   line 2- let priceAfterOneYear = "8,543";
+   line 7- const priceDifference = carPrice - priceAfterOneYear;
+   line 8- const percentageChange = (priceDifference / carPrice) * 100;*/
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+/* the expression doing changing the value of "10,000" to "10000" because comma count as part of a character after that 
+    changing the string variable type to number variable type. */

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,23 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// there are 6 variable declaration.
 
 // b) How many function calls are there?
+// there is only one function call.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+/* the expression movieLength % 60 represents the returns of the remainder after dividing one number by another 
+   in this case 8784 % 60 and it return the remainder 24. */
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+//This expression calculates the total full minutes in the movie by removing leftover seconds and converting seconds to minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+//result represent the total movie length using hours,minutes and seconds,the better name can be movieRunTime.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+/*the code works for different values of movieLength it present the input movieLength by calculating the remainder and subtracting 
+it with the initial input and using the method for the finding of the value for the rest of the variables and assign the values withe 
+the variables of hours,minutes and seconds */

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -1,4 +1,4 @@
-const penceString = "399p";
+const penceString = "340210p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
@@ -14,7 +14,6 @@ const pounds = paddedPenceNumberString.substring(
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
-
 console.log(`£${pounds}.${pence}`);
 
 // This program takes a string representing a price in pence
@@ -24,4 +23,26 @@ console.log(`£${pounds}.${pence}`);
 // Try and describe the purpose / rationale behind each step
 
 // To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 1. const penceString = "399p": initializes a string variable with the value "399p"
+
+/* 2. const penceStringWithoutTrailingP = penceString.substring(
+        0,
+        penceString.length - 1
+      ); : this part of the code have two steps,
+            - inside assigning of variable there is a function call that replace the string "399p" by "399"
+            - then assigning the variable penceStringWithoutTrailingP with new string "399" */
+
+/* 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); this initializes new string value that have
+          3 character if it's less than 3 it will add "0" in front of the string.*/
+
+/* 4.  const pounds = paddedPenceNumberString.substring(
+        0,
+        paddedPenceNumberString.length - 2
+      );  : this part of the code assigning const pound with value of string that length is 
+            reduced by -2 . */
+
+/* 5. const pence = paddedPenceNumberString
+        .substring(paddedPenceNumberString.length - 2)
+        .padEnd(2, "0"); : let's break it down this code parts it have two steps first one is .substring(paddedPenceNumberString.length - 2)
+                            Takes the last 2 characters of the string and the second is .padEnd(2, "0") Ensures the result 
+                            is at least length 2 if the length less than 2 it will add 0 at the end of the string. */