Program to print Hello World

void main() { 

   print("Hello World!"); 
}

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Program to demonstrate variables

 void main() {
//Declaring Variables
String name = "John";
String address = "USA";  
num age = 20; // used to store any types of numbers 
num height = 5.9;
bool working = false;
   
// printing variables value   
print("Name is $name");
print("Address is $address");
print("Age is $age");
print("Height is $height");
print("Is Working $working");
}

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Program to demonstrant const (to create a constant)

void main(){
const pi = 3.14;
num area=pi*10*10;
//pi = 4.23; // not possible  
print("Value of PI is $pi");
print("Area of circle with radius as 10 is $area");
}

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Program to demonstrate num datatype to create a integer variable

void main() {
 // Declaring Variables  
int num1 = 100; // without decimal point.
double num2 = 130.2; // with decimal point.
num num3 = 50;
num  num4 = 50.4;  

// For Sum   
num sum = num1 + num2 + num3 + num4;
   
// Printing Info   
print("Num 1 is $num1");
print("Num 2 is $num2");  
print("Num 3 is $num3");  
print("Num 4 is $num4");  
print("Sum is $sum");  
   
}

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Program to round a double variable

void main() {
// Declaring Variables
double prize = 1130.2232323233233; // valid.
print(prize.toStringAsFixed(2));
}

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program to demonstrate String datatype

void main() {
// Declaring Values     
String schoolName = "Diamond School";
String address = "New York 2140";   

// Printing Values
print("School name is $schoolName and address is $address");   
}

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Program to demonstrate multi line String

 void main() {
// Multi Line Using Single Quotes   
String multiLineText = '''
This is Multi Line Text
with 3 single quote
I am also writing here.
''';
   
// Multi Line Using Double Quotes   
String otherMultiLineText = """
This is Multi Line Text
with 3 double quote
I am also writing here.
""";
   
// Printing Information   
print("Multiline text is $multiLineText");
print("Other multiline text is $otherMultiLineText");
}

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program to demonstrate special characters

 void main() {
   
// Using \n and \t   
print("I am from \nUS.");
print("I am from \tUS.");
}

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program to demonstrate string to int

void main() {
String strvalue = "1";
print("Type of strvalue is ${strvalue.runtimeType}");   
int intvalue = int.parse(strvalue);
print("Value of intvalue is $intvalue");
// this will print data type
print("Type of intvalue is ${intvalue.runtimeType}");
}

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program to convert string to double

void main() {
String strvalue = "1.1";
print("Type of strvalue is ${strvalue.runtimeType}");
double doublevalue = double.parse(strvalue);
print("Value of doublevalue is $doublevalue");
// this will print data type
print("Type of doublevalue is ${doublevalue.runtimeType}");
}

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program to convert int to string

void main() {
int one = 1;
print("Type of one is ${one.runtimeType}");
String oneInString = one.toString(); 
print("Value of oneInString is $oneInString");
// this will print data type
print("Type of oneInString is ${oneInString.runtimeType}");
}

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program to convert double to int

void main() { 
   double num1 = 10.01;
   int num2 = num1.toInt(); // converting double to int

  print("The value of num1 is $num1. Its type is ${num1.runtimeType}");
  print("The value of num2 is $num2. Its type is ${num2.runtimeType}");
}

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example of list of strings

void main() {
List<String> names = ["Raj", "John", "Max"];
print("Value of names is $names");
print("Value of names[0] is ${names[0]}"); // index 0
print("Value of names[1] is ${names[1]}"); // index 1
print("Value of names[2] is ${names[2]}"); // index 2

  // Finding Length of List 
int length = names.length;  
print("The Length of names is $length");
}

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program to demonstrate set of strings

void main() {
Set<String> weekday = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
print(weekday);
}

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program to demonstrate map of strings

void main() {
Map<String, String> myDetails = {
   'name': 'John Doe',
   'address': 'USA',
   'fathername': 'Soe Doe'
};

print(myDetails['name']);
}

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program to demonstrate var datatype (var can store data of any datatype)

void main(){
var name = "John Doe"; // String
var age = 20; // int

print(name);
print(age);
}

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program to demonstrate runes (used to print ascii value of a variable)

void main() {

String value = "a";
print(value.runes); //prints ascii value of a
}

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program to demonstrate runtimeType (to find type of  variable at runtime)

void main() { 
   var a = 10;
   print(a.runtimeType); 
   print(a is int); // true
}

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program to demonstrate dynamic datatype (A language is dynamically typed if the data type of variables is known at run time)

void main() { 
   dynamic myVariable = 50;
   myVariable = "Hello";
   print(myVariable);
}

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program to demonstrate operators (+,-,*,/,%)

void main() {
 // declaring two numbers 
 int num1=10;
 int num2=3;
 
 // performing arithmetic calculation
 int sum=num1+num2;       // addition
 int diff=num1-num2;      // subtraction
 int unaryMinus = -num1;    // unary minus  
 int mul=num1*num2;       // multiplication
 double div=num1/num2;    // division
 int div2 =num1~/num2;     // integer division
 int mod=num1%num2;       // show remainder
 
//Printing info 
 print("The addition is $sum.");
 print("The subtraction is $diff.");
 print("The unary minus is $unaryMinus.");
 print("The multiplication is $mul.");
 print("The division is $div.");
 print("The integer division is $div2.");
 print("The modulus is $mod."); 
}

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program to demonstrate increment operator

void main() {
// declaring two numbers 
 int num1=0;
 int num2=0;
 
// performing increment / decrement operator  

// pre increment   
num2 = ++num1;
print("The value of num2 is $num2");

// reset value to 0 
num1 = 0;
num2 = 0;

// post increment  
num2 =  num1++;
print("The value of num2 is $num2");  
  
}

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program to demonstrate short hand assignment operators

void main() {
  double age = 24;
  age+= 1;  // Here age+=1 means age = age + 1.
  print("After Addition Age is $age");
  age-= 1;  //Here age-=1 means age = age - 1.
  print("After Subtraction Age is $age");
  age*= 2;  //Here age*=2 means age = age * 2.
  print("After Multiplication Age is $age");
  age/= 2;  //Here age/=2 means age = age / 2.
  print("After Division Age is $age");
}

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program to demonstrate relational operators (>,<,>=)

void main() {
  
 int num1=10;
 int num2=5;
 //printing info
 print(num1==num2); 
 print(num1<num2);
 print(num1>num2);
 print(num1<=num2);
 print(num1>=num2);
}

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program to demonstrate logical operators (&&,||,!=)

void main(){
  int userid = 123;
    int userpin = 456;

    // Printing Info
    print((userid == 123) && (userpin== 456)); // print true
    print((userid == 1213) && (userpin== 456)); // print false.
    print((userid == 123) || (userpin== 456)); // print true.
    print((userid == 1213) || (userpin== 456)); // print true
    print((userid == 123) != (userpin== 456));//print false

}

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program to check datatype of variable using is operator

void main() {
  String value1 = "Dart Tutorial";
  int age = 10;
  
  print(value1 is String);
  print(age is !int);
}

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program to read a string from console

import 'dart:io';

void main() {
  print("Enter name:");
  String? name  = stdin.readLineSync();
  print("The entered name is ${name}");
}

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program to read integer from console

import 'dart:io';

void main() {
  print("Enter number:");
  int? number = int.parse(stdin.readLineSync()!);
  print("The entered number is ${number}");
}

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program to read a double variable

import 'dart:io';

void main() {
  print("Enter a floating number:");
  double number = double.parse(stdin.readLineSync()!);
  print("The entered num is $number");
}

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program to demonstrate various types of strings

void main() {   
   String text1 = 'This is an example of a single-line string.';   
   String text2 = "This is an example of a single line string using double quotes.";   
   String text3 = """This is a multiline line   
string using the triple-quotes.
This is tutorial on dart strings.
""";   
   print(text1);  
   print(text2);   
   print(text3);   
}

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program to demonstrate string concatenation (joining two strings)

void main() {   
String firstName = "John";
String lastName = "Doe";
print("Using +, Full Name is "+firstName + " " + lastName+".");
print("Using interpolation, full name is $firstName $lastName.");  
  
}

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program to demonstrate unicode numbers of string alphabets

void main() {
   String str = "Hi";
   print(str.codeUnits);   //Example of code units
   print(str.isEmpty);     //Example of isEmpty
   print(str.isNotEmpty);  //Example of isNotEmpty
   print("The length of the string is: ${str.length}");   //Example of Length
}

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program to convert string to lowercase and uppercase

//Example of toUpperCase() and toLowerCase()
void main() { 
   String address1 = "Florida"; // Here F is capital
   String address2 = "TexAs"; // Here T and A are capital
   print("Address 1 in uppercase: ${address1.toUpperCase()}"); 
   print("Address 1 in lowercase: ${address1.toLowerCase()}"); 
   print("Address 2 in uppercase: ${address2.toUpperCase()}"); 
   print("Address 2 in lowercase: ${address2.toLowerCase()}"); 
}

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program to trim the string (means cutting of spaces from left and right side of the string)

//Example of trim()
void main() { 
  String address1 = " USA"; // Contain space at leading.
  String address2 = "Japan  "; // Contain space at trailing. 
  String address3 = "New Delhi"; // Contains space at middle.
  
  print("Result of address1 trim is ${address1.trim()}");
  print("Result of address2 trim is ${address2.trim()}");
  print("Result of address3 trim is ${address3.trim()}");
  print("Result of address1 trimLeft is ${address1.trimLeft()}");
  print("Result of address2 trimRight is ${address2.trimRight()}");
}

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program to demonstrate comparison of two strings

//Example of compareTo()
void main() { 
   String item1 = "Apple"; 
   String item2 = "Ant"; 
   String item3 = "Basket"; 
   
   print("Comparing item 1 with item 2: ${item1.compareTo(item2)}"); 
   print("Comparing item 1 with item 3: ${item1.compareTo(item3)}"); 
   print("Comparing item 3 with item 2: ${item3.compareTo(item2)}"); 
} 

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program to demonstrate replace a portion in string with another string

//Example of replaceAll()
void main() { 
String text = "I am a good boy I like milk. Doctor says milk is good for health.";
  
String newText = text.replaceAll("milk", "water"); 
 
print("Original Text: $text");
print("Replaced Text: $newText");  
   
} 

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program to splitting string into list of strings

//Example of split()
void main() { 
  String allNames = "Ram, Hari, Shyam, Gopal";

  List<String> listNames = allNames.split(",");
  print("Value of listName is $listNames");

  print("List name at 0 index ${listNames[0]}");
  print("List name at 1 index ${listNames[1]}");
  print("List name at 2 index ${listNames[2]}");
  print("List name at 3 index ${listNames[3]}");
   
} 

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program to convert number to string using toString function

//Example of toString()
void main() { 
int number = 20;     
String result = number.toString(); 
  
print("Type of number is ${number.runtimeType}");  
print("Type of result is ${result.runtimeType}");  
    
}   

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program to demonstrate substring(to take a portion out of string)

//Example of substring()
void main() { 
   String text = "I love computer"; 
   print("Print only computer: ${text.substring(7)}"); // from index 6 to the last index 
   print("Print only love: ${text.substring(2,6)}");// from index 2 to the 6th index 
} 

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program to reverse a string

void main() { 
  String input = "Hello"; 
  print("$input Reverse is ${input.split('').reversed.join()}"); 
} 

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program to capitalize first letter of String

void main() { 
  String text = "hello world"; 
  print("Capitalized first letter of String: ${text[0].toUpperCase()}${text.substring(1)}"); 
} 

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