Manchester| ITP-Jan-26 | Ofonime Edak | 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 1 is increasing the count, it is called increment in programming

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 = `${firstName[0]}${middleName[0]}${lastName[0]}`;
+console.log(initials); //CJK
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -17,7 +17,10 @@ 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 dir = ;
-const ext = ;
+const lastDotIndex = filePath.lastIndexOf(".");
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = filePath.slice(lastDotIndex + 1);
+console.log(dir);
+console.log(ext);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,12 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // 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
+
+//In the above expression num represent a variable that will store the result of that will be obtained from from the expression.
+// maximum and minimum are variables available on the global scope, as inputs.
+// They are evaluated first because of the parenthesis, this gives the precedence
+// The output from the parenthesis is now going to serve as the range for the Math.random() method.
+// Math.random() method produce random values from 0-1, with 0 and 1 inclusive and exclusive respectively
+// The range value makes Math.random() to return result from 0 to  range-1
+// the Math.floor() methods rounds down the value to the nearest whole number.
+// The result from th random operation is added back to the minimum value to return num.

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

@@ -1,2 +1,2 @@
-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?

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

@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;

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

@@ -1,5 +1,9 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
+// JavaScript is single-threaded because it executes tasks in a single flow using a call stack. The function was called before it was declared, 
+// It was also declared with const, which can not be hoisted to the top, like var.
+// this result to undefined.
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,4 +1,5 @@
-const cardNumber = 4533787178994213;
+let cardNumber = 4533787178994213;
+cardNumber = cardNumber.toString();
 const last4Digits = cardNumber.slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
@@ -7,3 +8,12 @@ const last4Digits = cardNumber.slice(-4);
 // 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 last4Digits variable should store the last 4 digits of cardNumber
+// 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 variable cardNumber is a number data type, numbers do not have slice methods or function, only string does.
+//TypeError: cardNumber.slice is not a function
+// Yes, it gives what i predicted

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";

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

@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -13,10 +13,20 @@ console.log(`The percentage change is ${percentageChange}`);
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
 
-// 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?
+//There are 5 function call in this code.
+// 1. Line 4 has 2 function call, .replaceAll() and Number()
+//2. Line 5 ditto line 4
+// 3. line 10 console.log() that logs the result to the console
 
+// 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 in this code is coming from line 5. The wrong use of the replaceAll syntax without a separator in the function arguments.
+// I will fix this problem by reading the documentation, to see the right way the syntax should be written.
+//Then i will add the comma where necessary
 // c) Identify all the lines that are variable reassignment statements
+ // line 4 and 5 are variable reassignment
 
 // d) Identify all the lines that are variable declarations
+ // line 1,2,7,8 are all variable declaration
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// this expression replaces the comma at the string with an empty string and the convert the string data type to a number data type

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

@@ -10,16 +10,25 @@ const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 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?
+// 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 % operator checks the remainder of that expression when being evaluated. It is similar to the remainder theorem in mathematics.
+// if it returns 0, even, if it returns value other than zero, it odd. it is mostly used for checks in programming
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The total time for this movie is 8760 second and fractional 24 seconds, line 4 is used to deduct the fractional 24 seconds
+// Then convert the whole number seconds to minute.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+// the variable result represent total movie duration in hours,minute and seconds.
+// const=runningTime
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// this code works for all movie running time and integer values.
+// for movie running time which are multiples of 60 it returns hours with 0 minutes and 0 seconds

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

@@ -25,3 +25,11 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = penceString.substring(0,penceString.length - 1);: used to strip off the last substring character 'p'
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): Used to add '0' to the start of the string if the string
+// length is less than 3, else if string length is 3 it does not pad.
+// 4.const pounds = paddedPenceNumberString.substring(0,paddedPenceNumberString.length - 2);: This expression copy the first character 
+// from every length character of the padded string
+// 5.const pence = paddedPenceNumberString .substring(paddedPenceNumberString.length - 2).padEnd(2, "0");: This expression add '0' to the end if the paddedString is not 
+// upto 2 characters
+// // 6.  this line is a function call to log the argument inside it to the console. it use template literals to get the values of the variables

Sprint-1/4-stretch-explore/chrome.md

@@ -6,13 +6,20 @@ Voila! You now have access to the [Chrome V8 Engine](https://www.cloudflare.com/
 Just like the Node REPL, you can input JavaScript code into the Console tab and the V8 engine will execute it.
 
 Let's try an example.
-
 In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
+It invokes the modal window and display Hello world
+
 What effect does calling the `alert` function have?
+It freezes the window till i click Ok before ii can make use of my computer
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
+const myName=prompt(`"What is your name?"`)
+return value myName=Edak
 
 What effect does calling the `prompt` function have?
+it invokes a modal window, and allows me to enter an input value
 What is the return value of `prompt`?
+it returns the value i entered "Edak"
+if "Edak" is entered an cancelled it returns null

Sprint-1/4-stretch-explore/objects.md

@@ -5,12 +5,23 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+I get `f log(){[native code]}` in return
 
 Now enter just `console` in the Console, what output do you get back?
+I get`console{debug: f,error:f,info:f,log:f....}`
 
 Try also entering `typeof console`
 
+I get `object`
 Answer the following questions:
 
 What does `console` store?
+The console store methods for debugging the console such as assert. clear,count,countReset,debug etc
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+console.log: Output a message to the console
+
+console.assert: Log an error message to the console if the first argument is false.
+`.` This is a member access operator used to access methods and properties of objects
+console store methods and functions