Javascript (JS) Pass by Reference and Pass by Value

Osarumense Idukpaye — Sat, 28 Jan 2023 20:28:35 +0000

Terms

Passing: To assign a value to a variable or, pass it to function as a parameter.

Pass by Value

Anytime a variable containing another value which is not an object or an array is passed along to let's say a function as a parameter, the variable being passed becomes a copy of the value it holds. As a result, the variable passed to the function will have its value unchanged despite whatever the function does with it, for example, reassign’s it or updates it.

let x = 60 
console.log (x) // 60

function boo (y){
    y = 70 
    console.log (y) // 70
}

foo(x) 
console.log (x) // 60 : unchanged value of the x variable

Pass by Reference

Anytime a variable containing another value which is an object or array is passed along to let say a function as a parameter, the variable is passed to the parameter as a ref to its object/array value. As a result, the variable passed to the function will have its value changed if for example it is updated with a new element of the key/value pair.

let x = {
    name:"john",
    age:22
} 
console.log (x) // {name:"john",age:22} 

function boo (y){
    y.statue = true
    console.log (y) // {name:"john",age:22, status:true} 
}

foo(x)
console.log (x) // {name:"john",age:22, status:true}

5 Debugging Tips that can Save you 5hrs of Debugging Time

Osarumense Idukpaye — Fri, 21 Oct 2022 23:14:17 +0000

1. Document Everything

You should always document everything from instructions on how to replicate the bug, to defined strategies on how to resolve the bug, to any side effect that results from a solution implementation. This is probably the most important one and I learnt this from working at Loxe Inc.

2. Error Logging

Always log your errors through a properly implemented error handler middleware and when an error occurs be sure to check your logs. I don't also forget the remove log statements from your debugged code. I learnt this from working at Loxe Inc.

3. Only refactor working code

When debugging it is best to work with the most simplistic-looking code piece of code to speed up the refactoring process and refactor after the code has been debugged.

4. Fix one problem at a time

This is also one major mistake most people make including myself of trying to resolve all the bugs at the same time before testing or grouping a lot of small bugs into one big bug, never do this. Always fix one bug at a time

5. Take Breaks

This can be linked to the spacing effect which refers to the finding that long-term memory is enhanced when learning events are spaced apart in time, rather than massed in immediate succession.
What this translates is that when trying to resolve bugs don't feel that you have to do it all in one go. it's okay to take breaks while resolving a bug.

DEV Community: Osarumense Idukpaye