While Loops in JavaScript

A while loop is more versatile than a for loop.

A while loop just needs a condition to keep running.

Creating a while loop

  • Add a condition.

for example

while ((rep<=10)

Run the look while the “rep” value is less than or equal to 10

  • Add the staring condition:

let rep = 1;

  • add the code to be executed:

console.log(‘lifting weights repetition ${rep}

  • Add the counter:

rep++;

let rep=1;
while (rep <=10) {
console.log('lifting weights repetition ${rep});
rep++;
}


While Loop doesn’t need a counter

Random variable – throwing a dice until we throw a 6

We don’t know how many times the dice has to be thrown, so we don’t need a counter

let dice = Math.trunc(Math.random() x 6) + 1;
console.log(dice);

while (dice !==6) {
console.log('Your rolled a ${dice}');
}



while (dice !==6) is the condition – roll the dice whilst the condition is not equal to 6

Making CSS Padding Responsive [2023]

First – you may want to use “padding-block:” – which is the padding for the top and the bottom only.

You can also use a “min()” statement or line of code, or whatever it’s called in CSS

If you type:

section {

padding-block: min(10vh, 10rem)

Min, Max & Clamp

Min

To use “min” – you may for example have a back-ground colour, with width:70% and max width:500px

width: min(500px, 70%)

Min will “look” for the smallest value – either 500px, or 70%

Min will choose the smallest value.

If you are on a mobile for example, 70% width, is less than 500px – so on mobile the background will be 70% of the viewport for a mobile.

If you are on a desktop computer, 500px will be less than 70% of the screen width – so the background will be 500px wide.

Responsive Equal Padding Top & Bottom

If you wanted to pad the top and bottom of text in the background:

padding-block: min (30px; 10%) ;

Max

width: max(500px, 70%)

max is the opposite – now it will use the maximum value.

on Mobile, 500px will be the largest

On Desktop – 70% will be the largest.

Padding with a Percentage

Calc Rem + VW

Yet another way to add padding, is to use “calc” and then add parameters/values for rem and vw

Rem (short for “root-em”) units dictate an element’s font size relative to the size of the root element. By default, most browsers use a font size value of 16px. 

The full form of VW is viewport width. It works like the percentage unit. Specifying 10vw is equivalent to occupying 10% of entire visible screen width.

This code works okay by the looks of it:

padding-block: calc(0.75rem + 0.5vw);
padding-left:  calc(0.75rem + 0.5vw);
padding-right: calc(0.75rem + 0.5vw);

Image & Text Aligned Side by Side Using CSS Grid

Here’s an example, that uses “padding: 2rem;” and “gap: 1rem:” to space the image and the

If you click on the CSS tab/button – everything below @media, is to provide a separate style and effect on mobile devices

To be honest, I having got a fecking clue with CSS Grid, I need a refresher – here’s a blog post I did earlier – https://businessdaduk.com/2022/11/21/css-grid-for-beginners-2022/

JavaScript – the for Loop [2023] for beginners/dummies/SEO-helmets

A for loop, is a loop that will loop through (go through) the elements in an array or the properties of an Object.

You can use it to update arrays, count the number of elements etc

Loops can execute a block of code several times.

With arrays, it’s common(ish) to run the same code over with a different value.

Image source

screenshot source

For Loops tend to be used with arrays (I think!)

The code below the array in the screenshot below, starting with “for”, loops through the variable called “names” above it.
Once it loops through it create “name” and then “console.log(name);” will get it to print on the console.log screen

  • console.log just provides a way of testing and outputting stuff using web developer tools, inspect element etc.

The code below, will do the same as above, but this time it will add “Hello there” before each of the names:

You can also add if conditions. For example, in the code below, the loop will check if “Maria” is in the list, and if so, will print out “Maria is in my list”

You can get the loop to stop once it finds “Maria” by using the “break” keyword.

The above code will print “Ed, John and then Maria and “Maria is in my list”. It will then stop and it won’t print all the names up to “Potter”.

As well as using the for loop with arrays, you can also use it with a single variable like “age”, and add an incremented – for example “age++”

The code shown below will print out and loop 10 times. starting at 0, and then 1, 2 etc. until finally the condition age <10 is no longer met

When the age is 10, it will stop.

A web dev example

Get all the links on a page, and return the number of the links on the page.

When the loop gets to the 6th link, it is no longer less than links.length, and so the loop stops:

(you can click the image to see a lager version, the important code is :

for (i = 0; i < links.length; i++)

To print out the final link, change “<links.length” to “<= links.length” – meaning “less than or equal to links.length”

for (i = 0; i <= links.length; i++)

For In Loops

For in loops, are the same as for loops except they are shorter to write but less flexible.

For Loop Example with an Array

Work out the age of people, given an array with their year of birth in it.

start with the array and then a new array, which will hold the ages:

const years = [1991, 2007, 1969, 2020]
const ages = [];

for(let I = 0; I <years.length; i++) {

ages.push (2023 – years [i] );

}

console.log(ages);

the “ages.push” code, will psh the results into the ages array

Continue & Break Statements

Continue is to exit the current iteration and move to the next one

Break will exit completely.

You can use with an if statement

continue loop statement

If the type of the current element, is not a string, then continue.

This will skip any elements/values that are not strings. Continue will exit the current iteration and not print to the console.log

Using break, will terminate the loop completely.

break loop statement

What are objects in Javascript? [2023]

Notes taken from the Udemy Course – the Complete JavaScript Course which you can enroll on here.

I’ve also robbed some screenshots from other sites, but linked to them in the “source”.

  • An object is a collection of properties
  • A property is an association between a name (key) and a value
  • A property’s value can be a function (but then it’s called a “method” for some reason)

Source

Objects provide a way to group values together in an organised fashion.

Objects can store lots of different types of data.

Objects can contain variables, functions or both.Variables found in objects are properties, while functions are methods.

In objects we define key-value pairs. The key is also called the “property name”.

Objects are normally declared within culry braces:

firstName is a “key” and the “value” is “Jonas”.

The name and the value, create a “key value pair”.

There are many ways of creating objects in JavaScript.

Using curly braces is called the “object literal syntax” because you’re writing down the literal object.

The order you write down objects doesn’t matter, unlike in arrays.

How do we get data from an object?

Dot Notation

Screenshot source

The first way to access data in an object is to use “dot notation”:

Dot notation is the most popular method to access the properties of an object.

let obj = {
  boxer: 'jab',
  muayThai: 'kick'
};
let strike = obj.boxer;
console.log(strike);
// jab

The dot notation in the example above is – let strike = obj.boxer;

Specify the name of the object, then add a dot, followed by the property name.

The syntax is objectName.propertyName;

Source

Bracket Notation

let obj = {
  boxer: 'jab',
  muaythai: 'kick'
};
let strike = obj['boxer'];
console.log(strike);
// jab

You can read a much better article about dot and bracket notation – here –> codeburst.io or here —> plainenglish.io

How do you create objects?

It is a common practice to declare objects with the const keyword.

There are two methods by which you can create an object: an object literal and the object constructor. 

Source

let’s create an object named myCup and give it properties named color, volume, and weight as follows:

let myCup = new Object();
myCup.color = "transparent";
myCup.volume = 1;
myCup.weight = 0.5;

We can write the same object in a shorter notation. Comma-delimited list of  pairs of property names and associated values, enclosed in curly braces:

let myCup = {
 color: "transparent",
 volume: 1,
 weight: 0.5
}


Above, we declare a variable in the same way with: let myCup equals and then curly brace.

source

If you are making multiple objects, it’s best to use the object constructor.

You can use a constructor to create a new object by calling the constructor with the new keyword. The new keyword will create an instance of an object and bind the this keyword to the new object.

The this keyword is a reference to the object itself.

function Fighter(name, age, nationality) { 
    this.name = name; 
    this.age = age; 
    this.nationality = nationality; 
    this.bio = function () { 
        console.log(`My name is ${this.name}. I'm ${this.age} years old. I'm from ${this.nationality}`) 
    } 
};

const oladele = new Profile("Izzy", 29, "Nigeria" );
console.log(oladele.bio()); //My name is Izzy. I'm 29 years old. I'm from Nigeria

More info about constructors at Freecodecamp.org

Here’s another example, using the this keyword from w3schools

<script>
// Constructor function for Person objects
function Person(first, last, age, eye) {
  this.firstName = first;
  this.lastName = last;
  this.age = age;
  this.eyeColor = eye;
}

// Create a Person object
const myFather = new Person("John", "Doe", 50, "blue");

// Display age
document.getElementById("demo").innerHTML =
"My father is " + myFather.age + "."; 
</script>

The above code gives the output “my father is 50”. (which is printed to the paragraph with the id of “demo”)

Adding a method to an object

We can add a method simply by adding another property that is a function. This function will be able to read the values of the object and work with them.

We will add an example that will print out the color of the table.

myTable.whatIsMyColor = function() {
 console.log("My color is: " + this.color);
};

source

source

Adding a new property to an object

In JavaScript you can add a property to an object after it has been created.

The following statement adds the age property to the fighter object and assigns 22 to it:

fighter.age = 22;






Deleting a property of an object

Simply use the delete operator

delete fighter.age;

Checking if a property exists

To check if a property exists in an object, you use the in operator:

propertyName in objectName

The in operator returns true if the propertyName exists in the objectName.

The following example creates an employee object and uses the in operator to check if the ssn and employeeId properties exist in the object:

let employee = {
    firstName: 'Peter',
    lastName: 'Doe',
    employeeId: 1
};

console.log('ssn' in employee);
console.log('employeeId' in employee);Code language: JavaScript (javascript)

Output:

false
true

Source

Javascript Arrays for Beginners (2023)

Arrays hold values.

An array is an ordered list of values.

Arrays are 0-based, in that the first value is 0, not 1 in terms of its position.

A JavaScript array has the following characteristics:

  1. First, an array can hold values of mixed types. For example, you can have an array that stores elements with the types number, string, boolean, and null.
  2. Second, the size of an array is dynamic and auto-growing. In other words, you don’t need to specify the array size up front.

source

W3schools describes an array as a “special variable, which can hold more than one value”.

An array can hold many values under a single name, and you can access the values by referring to an index number.

arrays w3schools

source

Creating & Fetching JavaScript arrays

JavaScript provides you with two ways to create an array. 

It is a common practice to declare arrays with the const keyword.

Image source

You can also use the following code to create a new array:

let values = new Array();

or

let values = [item1,item2,...]

Once you’ve created your array, you can print the values to the console.log with the code:

console.log(values);



With “values” being the name of the array.

You can call “values.length” to get the length of the array

console.log(values.length);

Again, in the above code “values” is the name of the array.

You can define and name an array, and then “push” values into it later:

The above code will add a single value of 5 to the array named “values”.

console.log(values[1]); will print the second value – 7

console.log(values[0]); will print the first value – 5

In summary – to create an array, it’s generally best to use the “const” keyword, or the “new” keyword.

Adding & Changing Stuff Within Arrays

Below, the array name is used,and the variable number to update, the first variable.

You can try it yourself on the w3 schools website.

Accessing Arrays

You access an array element by referring to the index number:

accessing arrays

You can also loop through arrays

Javascript Functions for Beginners

A function is a piece of code, that can be reused.

It’s similar to a variable but doesn’t hold a value like a variable does. So it’s not that much like a variable, but kind of is.

Screenshots are from the brilliant Javascript Course on Udemy here

The code on lines 16 and 17 shown in the image above, creates the function. It is named “logger”.

the shorter code logger(); is used to/for “invoke”, “running”, or “calling” the function.

Function Declerations Vs Expressions

Function Declerations

When you create a function with a name, then it is a function decleration.

Function statements, declare a function. A declared function can be used later when it is “invoked” or “called”.

Function declerations must start with “function”.

For example:

function mma() {

return 8;

}

The functioned mma is declared. to invoke it use the code mma();

You can call function declerations, above the code that creates it.

Function Expressions (good article here)

A JavaScript function can also be defined using an expression.

A function expression can be stored in a variable:

Image source

Function expressions are invoked to avoid polluting the global scope. Instead of your program being aware of many different functions, when you keep them anonymous, they are used and forgotten immediately.

To summarize, function declarations are utilized when you desire to establish a function in the global scope that can be accessed anywhere in your code. On the other hand, function expressions are employed to confine the accessibility of the function, reduce the weight of the global scope, and maintain a neat syntax.

JavaScript Arrow Function

Arrow functions have shorter syntax

They are best suited to non-method functions

source

Functions Calling Other Functions

An example, might be a function that cuts up fruit pieces, and then sends the result to a function that blends it into a smoothie.

The start function used above, will print out “I am first bo! 222222!!!”

Functions Summary

A function is like a procedure. It has tasks and calculates a value.

A function requires input and must return an output.

Functions need to be defined with the word “function” and brackets ()

Brackets can also be called paranthesies, and the input is sometimes called “arguments” or “parameters”.

Image source

Image Source

Excel – Find Cells that contain 2 Specific Words

If you are for example, searching an e-commerce site crawl or download for football goals…

If you want to identify cells that contain, for example “football” and “goal”, you can use the formula:

With the URLs in column A, in column B add the formula:

=AND(ISNUMBER(SEARCH("football",A2)),ISNUMBER(SEARCH("goal",A2)))

To find cells that contain “football” OR “goal”, use:

=AND(ISNUMBER(SEARCH("football",A2)),ISNUMBER(SEARCH("goal",A2)))


Bulk checking Hreflang Tags for SEO on an eCommerce Store (With Screaming Frog)

Find URLs that should have a hreflang tag – Indexable URLs

Crawl the website with Screaming Frog

Download the “internal” report on first tab

Filter relevant columns to find all URLs that return 200 (Status Code), are indexable (Indexability)

Paste the filtered sheet into a new tab/sheet and delete irrelevant columns so you just have URL and Canonical columns

Use =Exact formula to find all URLs that match the canonical URL

Filter Canonical URL column to “true”

You should be left with all URLs that are indexable – i.e. 200 status codes and URLs that exactly match canonical URLs.

Copy all the URLs that remain

Find Missing Hreflangs – Paste Back into Screaming Frog in List Mode

Use List Mode and Copy the URLs into screaming frog and crawl.

Check the crawl and go to the hreflang tab – order by hreflang “Occurences”

Export hreflang

Check the Screaming Frog Filters

Just discovered we have lots of non-200 hreflang links.

It’s definitely worth checking the filters on the hreflang tab

Official documentation from Screaming Frog here.

Excel & SEO – Removing Folders in URL Paths (Just leaves page URN)

The easiest thing to do is use regex and the Search function

Remove text before a forward slash in Excel:

To remove text or URL paths after a slash, use find and replace then /*

To remove the slash after the domain use Find and Replace – Example.com/ and replace with “nothing”:

You can then concatenate the domain back in place at the end, if you need to

Also had this reply from Reddit

*I’ve never really got my head around URLs, URIs and URNs. I think the product-name that I’m after, is a URN.

https://myshop.com/category-folder/product-name

Image source

Image source