added content to - prototypal inheritance, implicti type casting, keyed collections, structured data, break continue, labeled statements, comparison operators, string operators, conditional operators (#2032)

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/106-javascript/content/102-javascript-datatypes/101-object/101-prototypal-inheritance.md

@@ -1 +1,14 @@
-# Prototypal inheritance
+# Prototypal inheritance
+
+In JavaScript, objects have a special hidden property `[[Prototype]]`, that is either null or references another object. That object is called "a prototype".
+
+When we read a property from object, and it's missing, JS automatically takes it from the prototype. This is called "protoypal inheritance".
+
+Syntax:
+
+`ChildObject.__proto__ = ParentObject`
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink badgeText='Official Website' colorScheme='blue' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain'>JavaScript MDN Docs</BadgeLink>
+<BadgeLink badgeText='Official Website' colorScheme="blue" href='https://www.geeksforgeeks.org/prototypal-inheritance-using-__proto__-in-javascript/'>GeeksForGeeks – JavaScript Tutorial</BadgeLink>
+<BadgeLink badgeText='Official Website' colorScheme="blue" href='https://javascript.info/prototype-inheritance'>The Modern JavaScript Tutorial</BadgeLink>

content/roadmaps/106-javascript/content/103-javascript-type-casting/102-implicit-type-casting.md

@@ -1,6 +1,9 @@
 # Implicit Type Casting
 
-Implicit type casting happens when JavaScript automatically converts one data type to another to meet the expectations of the process. as for example passing a number when it expects a string like `"foo" + 1`, the Number `1` is implicitly converted into a string and the expression returns `"foo1"`.
+Implicit type conversion happens when the compiler or runtime automatically converts data types. JavaScript is loosely typed language and most of the time operators automatically convert a value to the right type.
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.geeksforgeeks.org/javascript-type-conversion/'>GeeeksForGeeks - JavaScript Tutorials</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.w3schools.com/js/js_type_conversion.asp'>W3Schools - JavaScript Tutorials</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.tutorialspoint.com/explain-typecasting-in-javascript'>TutorialsPoint - JavaScript Tutorials</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://dev.to/promisetochi/what-you-need-to-know-about-javascripts-implicit-coercion-e23'>What you need to know about Javascript's Implicit Coercion</BadgeLink>

content/roadmaps/106-javascript/content/104-javascript-data-structures/101-keyed-collections/readme.md

@@ -1 +1,10 @@
-# Keyed collections
+# Keyed collections
+
+Keyed collections are collections of data that are ordered by a key and not index. They are associative in nature.
+
+`Map` and `Set` objects contain elements which are iterable in the order of insertion.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Keyed_collections'>JavaScript MDN Docs</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.tutorialspoint.com/keyed-collections-in-javascript'>Tutorialspoint – JavaScript Tutorial</BadgeLink>
+<BadgeLink badgeText='Read' colorScheme="yellow" href='https://medium.com/@jimmyfarillo/keyed-collections-in-javascript-set-vs-map-vs-weakset-vs-weakmap-f50d86052da2'>Medium - Keyed Collections in JavaScript</BadgeLink>

content/roadmaps/106-javascript/content/104-javascript-data-structures/102-structured-data/readme.md

@@ -1 +1,8 @@
-# Structured data
+# Structured data
+
+Structured data is used by search-engines, like Google, to understand the content of the page, as well as to gather information about the web and the world in general.
+
+It is also coded using in-page markup on the page that the information applies to.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developers.google.com/search/docs/appearance/structured-data/intro-structured-data'>Google Developers docs</BadgeLink>

content/roadmaps/106-javascript/content/106-javascript-loops-iterations/102-break-continue/100-labeled-statements.md

@@ -1,6 +1,9 @@
 # Labeled Statements
 
-The labeled statement can be used with `break` or `continue` statements. It is prefixing a statement with an identifier that you can refer to.
+JavaScript label statements are used to prefix a label to an identifier. It can be used with `break` and `continue` statement to control the flow more precisely.
+
+A label is simply an identifier followed by a colon`(:)` that is applied to a block of code.
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
-<BadgeLink colorScheme='yellow' badgeText='Read' href= 'https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label'>Label Statements</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label'>JavaScript MDN Docs</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.tutorialspoint.com/What-are-label-statements-in-JavaScript'>Tutorialspoint – JavaScript Tutorial</BadgeLink>

content/roadmaps/106-javascript/content/106-javascript-loops-iterations/102-break-continue/readme.md

@@ -1,7 +1,10 @@
-# Break Continue
+# Break continue
 
-The `break` and `continue` statements are used to "jump out" of a loop. When executed, the `break` statement will terminate the loop entirely; Whereas `continue` will terminate only the current iteration, and continue execution of the loop's next iteration. 
+`break` statement, without a label reference, can only be used to jump out of a loop or a switch block.
+
+`continue` statement, with or without a label reference, can only be used to skip one loop iteration.
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
-<BadgeLink colorScheme='blue' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/break'>break</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/continue'>JavaScript MDN Docs - continue statement</BadgeLink>
-<BadgeLink colorScheme='blue' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/continue'>continue</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/break'>JavaScript MDN Docs - break statement</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.w3schools.com/js/js_break.asp'>W3Schools – JavaScript Tutorial</BadgeLink>

content/roadmaps/106-javascript/content/108-javascript-expressions-and-operators/101-omparison-operators.md

@@ -1,7 +1,8 @@
 # Comparison Operators
 
-Comparison operators are the operators that compare values and return true or false.
+Comparison operators are the operators that compare values and return true or false. The operators include: `>`, `<`, `>=`, `<=`, `==`, `===`, `!==` and `!===`
-The operators include : `>`, `<`, `>=`, `<=`, `==`, `===`, `!==` and `!===`
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.w3schools.com/js/js_comparisons.asp'>W3Schools - JavaScript Tutorials</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#comparison_operators'>JavaScript MDN Docs</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#comparison_operators'>Comparison operators</BadgeLink>

content/roadmaps/106-javascript/content/108-javascript-expressions-and-operators/106-string-operators.md

@@ -1,7 +1,9 @@
 # String Operators
 
-Strings are useful for holding data that can be represented in text form. Some of the most-used operators on strings are to build and concatenate them using this string operators: `+` (Concatenate), `+=` (Concatenate Assignment).
+In addition to the comparison operators, which can be used on string values, the concatenation operator (`+`) concatenates two string values together, returning another string that is the union of the two operand strings.
+
+The shorthand assignment operator `+=` can also be used to concatenate strings.
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
-<BadgeLink colorScheme='yellow' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#string_operators'>Arithmetic Operators - MDN</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#string_operators'>JavaScript MDN Tutorials</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://javascript.info/operators#string-concatenation-with-binary'>String Concatenation - JavaScript.info</BadgeLink>

content/roadmaps/106-javascript/content/108-javascript-expressions-and-operators/107-conditional-operators.md

@@ -1,6 +1,13 @@
-# Conditional Operators
+# Conditional operators
 
-The conditional operator (or "ternary" operator) is a shorthand `if...else` statement. The syntax is: `condition ? expression1 : expression2;`. That is, the operator will execute `expression1` if the condition is `truthy`, and otherwise `expression2` if the condition is `falsy`.
+Conditional oprator also known as Ternary operator is the only JS operator that takes three operands.
+
+The operator can have one of two values based on a condition.
+
+Syntax:
+
+`condition ? val_for_true : val_for_false `
 
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
-<BadgeLink colorScheme='blue' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#conditional_ternary_operator'>Conditional Operator</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#conditional_operator'>JavaScript MDN Docs</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://www.w3schools.com/js/js_comparisons.asp'>W3Schools - JavaScript Tutorials</BadgeLink>