Control Flow Statements in Dart

Control Flow Statements are used to control the flow of execution of the program. Control Flow Statements are used to alter the flow of the program based on certain conditions.

Types of Control Flow Statements

There are three types of Control Flow Statements in Dart:

Decision Making Statements
Looping Statements
Jump Statements

Decision Making Statements

Decision Making Statements are used to make decisions based on certain conditions. There are three types of Decision Making Statements in Dart:

if Statement
if-else Statement
if-else-if Ladder

if Statement

if Statement is used to execute a block of code if a certain condition is true. The syntax of if Statement is:

if(condition){
    //statements to be executed if the condition is true
}

if-else Statement

if-else Statement is used to execute a block of code if a certain condition is true and another block of code if the condition is false. The syntax of if-else Statement is:

if(condition){
    //statements to be executed if the condition is true
}
else{
    //statements to be executed if the condition is false
}

if-else-if Ladder

if-else-if Ladder is used to execute a block of code if a certain condition is true and another block of code if the condition is false. There can be multiple else-if blocks in an if-else-if Ladder. The syntax of if-else-if Ladder is:

if(condition1){
    //statements to be executed if the condition1 is true
}
else if(condition2){
    //statements to be executed if the condition2 is true
}
else if(condition3){
    //statements to be executed if the condition3 is true
}
else{
    //statements to be executed if all the conditions are false
}

Looping Statements

Looping Statements are used to execute a block of code repeatedly. There are three types of Looping Statements in Dart:

for Loop
while Loop
do-while Loop

for Loop

for Loop is used to execute a block of code repeatedly for a fixed number of times. The syntax of for Loop is:

 
for(initialization; condition; updation){
    //statements to be executed repeatedly
}

while Loop

while Loop is used to execute a block of code repeatedly for an unknown number of times. The syntax of while Loop is:

 
while(condition){
    //statements to be executed repeatedly
}

do-while Loop

do-while Loop is used to execute a block of code repeatedly for an unknown number of times. The syntax of do-while Loop is:

 
do{
    //statements to be executed repeatedly
}while(condition);

Jump Statements

Jump Statements are used to alter the flow of the program. There are three types of Jump Statements in Dart:

break Statement
continue Statement
return Statement

break Statement

break Statement is used to terminate the loop or switch statement. The syntax of break Statement is:

break;

continue Statement

continue Statement is used to skip the current iteration of the loop. The syntax of continue Statement is:

continue;

return Statement

return Statement is used to return a value from a function. The syntax of return Statement is:

return value;

Example

 
void main(){
    //if Statement
    int a = 10;
    if(a > 5){
        print("a is greater than 5");
    }
 
    //if-else Statement
    int b = 10;
    if(b > 5){
        print("b is greater than 5");
    }
    else{
        print("b is less than or equal to 5");
    }
 
    //if-else-if Ladder
    int c = 10;
    if(c > 5){
        print("c is greater than 5");
    }
    else if(c > 3){
        print("c is greater than 3");
    }
    else{
        print("c is less than or equal to 3");
    }
 
    //for Loop
    for(int i = 0; i < 5; i++){
        print(i);
    }
 
    //while Loop
    int j = 0;
    while(j < 5){
        print(j);
        j++;
    }
 
    //do-while Loop
    int k = 0;
    do{
        print(k);
        k++;
    }while(k < 5);
 
    //break Statement
    for(int i = 0; i < 5; i++){
        if(i == 3){
            break;
        }
        print(i);
    }
 
    //continue Statement
    for(int i = 0; i < 5; i++){
        if(i == 3){
            continue;
        }
        print(i);
    }
 
    //return Statement
    int sum = add(5, 10);
    print(sum);
} 
 
int add(int a, int b){
    return a + b;
}

Output

a is greater than 5
b is greater than 5
c is greater than 5

0
1
2
3
4

0
1
2
3
4 

0
1
2
3
4

0
1
2

0
1
2
4 


15

Conclusion

In this tutorial, we learned about Control Flow Statements in Dart. In the next tutorial, we will learn about Functions in Dart.

Quiz

Which of the following is not a Decision Making Statement in Dart?

a) if Statement

b) if-else Statement

c) if-else-if Ladder

d) for Loop
Which of the following is not a Looping Statement in Dart?

a) for Loop

b) while Loop

c) do-while Loop

d) if-else-if Ladder
Which of the following is not a Jump Statement in Dart?

a) break Statement

b) continue Statement

c) return Statement

d) if-else-if Ladder

What will be the output of the following Dart code?

void main(){
    int a = 10;
    if(a > 5){
        print("a is greater than 5");
    }
    else{
        print("a is less than or equal to 5");
    }
}

a) a is greater than 5

b) a is less than or equal to 5

c) a is greater than 5 a is less than or equal to 5

d) Compilation Error

What will be the output of the following Dart code?

void main(){
    int a = 10;
    if(a > 5){
        print("a is greater than 5");
    }
    else if(a > 3){
        print("a is greater than 3");
    }
    else{
        print("a is less than or equal to 3");
    }
}

a) a is greater than 5

b) a is greater than 3

c) a is less than or equal to 3

d) Compilation Error

What will be the output of the following Dart code?
```
void main(){
    for(int i = 0; i < 5; i++){
        print(i);
    }
}
```
a) 0 1 2 3 4

b) 1 2 3 4 5

c) 0 1 2 3 4 5

d) Compilation Error

What will be the output of the following Dart code?

void main(){
    int i = 0;
    while(i < 5){
        print(i);
        i++;
    }
}

a) 0 1 2 3 4

b) 1 2 3 4 5

c) 0 1 2 3 4 5

d) Compilation Error

What will be the output of the following Dart code?

void main(){
    int i = 0;
    do{
        print(i);
        i++;
    }while(i < 5);
}

a) 0 1 2 3 4

b) 1 2 3 4 5

c) 0 1 2 3 4 5

d) Compilation Error

What will be the output of the following Dart code?

void main(){
    for(int i = 0; i < 5; i++){
        if(i == 3){
            break;
        }
        print(i);
    }
}

a) 0 1 2 3 4

b) 1 2 3 4 5

c) 0 1 2 3 4 5

d) Compilation Error

What will be the output of the following Dart code?

void main(){
    for(int i = 0; i < 5; i++){
        if(i == 3){
            continue;
        }
        print(i);
    }
}

a) 0 1 2 3 4

b) 1 2 3 4 5

c) 0 1 2 3 4 5

d) Compilation Error

Operators in Dart Loops in Dart