Loops in Dart

Looping

In Programming, looping is used to execute the block of code repeatedly for a specified number of times or until it meets a specified condition. For E.g, For printing name 10 times, you can use loop.

Types of Loop

  • For Loop
  • For each Loop
  • While Loop
  • Do While Loop

For Loop

This is the most common type of loop. You can use for loop to run a block of code multiple times according to condition.

Syntax

for(initialization; condition; increment/decrement){
            statements;
}
  • Initialization is executed (one time) before the execution of the code block.
  • Condition defines the condition for executing the code block.
  • Increment/Decrement is executed (every time) after the code block has been executed.

Example To Print 1 To 10 Using For Loop Increment

void main() {
  for (int i = 1; i <= 10; i++) {
    print(i);
  }
}
Show Output

Example To Print 10 To 1 Using For Loop Decrement

void main() {
  for (int i = 10; i >= 1; i--) {
    print(i);
  }
}
Show Output

For each Loop

The for each loop iterates over all elements of list or variable. It is a higher order function.

Example For List

void main(){
  List<String> footballplayer=['Ronaldo','Messi','Neymar','Hazard'];
  footballplayer.forEach( (names)=>print(names));
}
Show Output

Example For Variable

void main(){
   var name=['ram','hari','aastha','kiran'];
   name.forEach((var names)=>print(names));
 }
Show Output

While Loop

The body of the loop will run until and unless the condition is true. You must write condition first before statements.

Syntax

while(condition){  
       //statement(s);  
      // Increment (++) or Decrement (--) Operation;  
}  

Example To Print 1 To 10 Using While Loop Increment

void main() {
  int i = 1;
  while (i <= 10) {
    print(i);
    i++;
  }
}
Show Output

Example To Print 10 To 1 Using While Loop Decrement

void main() {
  int i = 10;
  while (i >= 1) {
    print(i);
    i--;
  }
}
Show Output

Do While Loop

Do while loop is used to run a block of code multiple times. Simply you can say, the body of the loop will be executed first and then the condition is tested.

Syntax

do{
    statement1;
    statement2;
    .
    .
    .
    statementN;
}while(condition);

Example To Print 1 To 10 Using Do While Loop Increment

void main() {
  int i = 1;
  do {
    print(i);
    i++;
  } while (i <= 10);
}
Show Output

Example To Print 10 To 1 Using Do While Loop Decrement

void main() {
  int i = 10;
  do {
    print(i);
    i--;
  } while (i >= 1);
}
Show Output