Adding content to 100-dart-basics

src/roadmaps/flutter/content/100-dart-basics/100-dart-pad.md

@@ -1,7 +1,8 @@
-# Dart pad
+# DartPad
 
-DartPad is an open source tool that lets you play with the Dart language in any modern browser.
+DartPad is an online tool that allows developers to write and run Dart code snippets. It can also be used to run Flutter code, making it a convenient way to try out Flutter apps and widgets without having to set up a full development environment.
 
 Visit the following resources to learn more:
 
 - [DartPad](https://dart.dev/tools/dartpad)
+- [DartPad in Tutorials](https://dart.dev/resources/dartpad-best-practices)

src/roadmaps/flutter/content/100-dart-basics/101-variables.md

@@ -1,5 +1,13 @@
 # Variables
 
+In Flutter, variables are used to store values. There are two types of variables in Flutter: 
+
+- local variables: These are declared within a function and are only accessible within that function
+- Instance variables: They are declared within a class and are accessible throughout the entire class. 
+
+Variables in Flutter can store values of different data types, such as numbers, strings, booleans, and more.
+
 Visit the following resources to learn more:
 
 - [Variables](https://dart.dev/guides/language/language-tour#variables)
+- [Dart - Variables](https://howtoflutter.dev/dart/variables/)

src/roadmaps/flutter/content/100-dart-basics/102-built-in-types.md

@@ -1,5 +1,17 @@
-# Built in types
+# Built-in Types
+
+There are several built-in data types, including:
+
+- int: used to store integers
+- double: used to store floating-point numbers
+- String: used to store text
+- bool: used to store true or false values
+- List: used to store ordered collections of objects
+- Map: used to store unordered collections of key-value pairs
+
+Additionally, there are other complex data types like dynamic, var, and Object in Dart programming language which is used in Flutter.
 
 Visit the following resources to learn more:
 
 - [Built-in types](https://dart.dev/guides/language/language-tour#built-in-types)
+- [Overview of Built-in Types](https://dart.dev/guides/language/coming-from/js-to-dart#built-in-types)

src/roadmaps/flutter/content/100-dart-basics/103-functions.md

@@ -5,3 +5,4 @@ Dart is a true object-oriented language, so even functions are objects and have
 Visit the following resources to learn more:
 
 - [Functions](https://dart.dev/guides/language/language-tour#functions)
+- [Dart Function](https://www.javatpoint.com/dart-function)

src/roadmaps/flutter/content/100-dart-basics/104-operators.md

@@ -1,5 +1,16 @@
 # Operators
 
+Operators are symbols or keywords used to perform operations on values. There are several types of operators available in Flutter:
+
+- Arithmetic operators: used to perform mathematical operations like addition (+), subtraction (-), multiplication (*), division (/), and more.
+- Relational operators: used to compare values and return a boolean result (==, !=, >, <, >=, <=).
+- Logical operators: used to perform logical operations like AND (&&), OR (||), and NOT (!).
+- Assignment operators: used to assign values to variables (=, +=, -=, *=, /=, %=).
+- Ternary operator: a shorthand way of writing simple if-else statements (condition ? if_true : if_false).
+
+These operators can be used to perform operations on values, variables, and expressions in Flutter.
+
 Visit the following resources to learn more:
 
 - [Operators](https://dart.dev/guides/language/language-tour#operators)
+- [Operators in Dart](https://www.geeksforgeeks.org/operators-in-dart/)

src/roadmaps/flutter/content/100-dart-basics/105-control-flow-statements.md

@@ -1,5 +1,18 @@
-# Control flow statements
+# Control Flow Statements
+
+In Dart, control flow statements are used to control the flow of execution of a program. The following are the main types of control flow statements in Dart:
+
+- if-else: used to conditionally execute code based on a boolean expression.
+- for loop: used to repeat a block of code a specific number of times.
+- while loop: used to repeat a block of code as long as a given condition is true.
+- do-while loop: similar to the while loop, but the block of code is executed at least once before the condition is evaluated.
+- switch-case: used to select one of several code blocks to execute based on a value.
+- break: used to exit a loop early.
+- continue: used to skip the current iteration of a loop and continue with the next one.
+
+These control flow statements can be used to create complex logic and control the flow of execution in Dart programs.
 
 Visit the following resources to learn more:
 
 - [Control flow statements](https://dart.dev/guides/language/language-tour#control-flow-statements)
+- [Dart Control Flow Statements](https://www.w3adda.com/dart-tutorial/dart-control-flow-statements)