London | 26-ITP-January | Eugenie Ahangama | Sprint 2 | coursework/sprint 2

[Eugenie-A]

Learners, PR Template

Self checklist

• I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
• My changes meet the requirements of the task
• I have tested my changes
• My changes follow the style guide

Changelist

I worked through the Sprint 2 exercises by going through the starter code, identifying the main errors and making sure I understood why the logic wasn't working. I then wrote tests in the debug section to clearly show the issues before fixing anything. After that, I implemented the correct JavaScript behaviour so the function produced the right results. Finally, in the interpret task, I explained what the original code was doing, why it failed and how my fixes solved those problems.

MDN References I used:
String.prototype.slice()
Number() constructor
Template literals
console.assert()
String.prototype.split()
Array.prototype.map()
Remainder operator (%)
String.prototype.padStart()
String.prototype.substring()
String.prototype.replace()
String.prototype.trim()
String.prototype.toUpperCase()
Function parameters
Return

Questions

What's the best way to structure a debugging process?

[cjyuan]

What type of value do you expect your function to return? A number or a string?
Does your function return the type of value you expect?

Different types of values may appear identical in the console output, but they are represented and treated differently in the program. For example,

  console.log(123);              // Output 123
  console.log("123");            // Output 123
  
  // Treated differently in the program
  let sum1 = 123 + 100;         // Evaluate to 223 -- a number
  let sum 2 = "123" + 100;      // Evaluate to "123100" -- a string.

[Eugenie-A]

I expected the function to return a number, not a string.
No, my function didn't return the type of value I was expecting it to, but rather it was returned as a string due to .toFixed(1).
I updated it to return Number( (weight / (height * height)).toFixed(1) ); - This keeps the rounding to 1 decimal place but converts back to a number.

[cjyuan]

What's the best way to structure a debugging process?

I do not understand what you mean. Can you elaborate?

[Eugenie-A]

What's the best way to structure a debugging process?

I do not understand what you mean. Can you elaborate?

I'm trying to get better at debugging JavaScript code in a consistent, step by step way especially when fixing broken functions or understanding why something fails.

So what I'm asking is what are some reliable structured debugging habits or checklists that experienced developers use?

[cjyuan]

The key of debugging is to find out which expression does not evaluate to the expected value or which variable does not hold the expected value.

For small amount of code, we can output the value of suspected expressions or variables.
For larger code base, we can use a debugger. We can use it to set break points, inspect value of variables, and trace the execution of the the code line by line.