Flow control describes the order in which the statements will be execute at run time.

Flow Control

Selection Statements -

1. if else - The argument to the if statement should be boolean type, if we are providing any other type we will get compile time error

int x = 10;

if (x == 20){

System.out.print("Hello");

}else{

System.out.print("Hi");

}

} // Output - Hi

2. Switch - if several options are possible then we have to go for switch case, after every label we have to use break statement otherwise if one condition gets true from there onward all label will be execute.

int x = 3;

switch(x){

case 1: System.out.print("One");

break;

case 2: System.out.print("Two");

break;

case 3: System.out.print("Three");

break;

case 4: System.out.print("Four");

break;

case default: System.out.print("NA");

break;

} // Output - Three

Iterative Statements -

1. While Loop - if we don't know the number of iteration in advance then best suitable loop is while loop, the argument in while loop must be boolean type only.

int a = 10, b = 20;

while(a<b){

System.out.print("True");

}

System.out.print("False");

}

2. do - while loop - If we want to execute loop body at least one time the we have to use do - while loop

int a = 10, b = 20;

do{

System.out.print("Hello");

}while(a>b)

System.out.print("Hi");

3. for() loop - this is the most commonly used loop, if we know the number of iteration then for loop is best choice

syntax : for(initialization;condition;increment decrement){

body }

for(int i=0;i<=10;i++){

System.out.print(x);

}

4. for-each() - also known as enhanced for loop, introduced in 1.5 version. this is the most convenient loop to retrieve the element of array and collection.

int[ ] a = {10, 20, 30, 40};

for loop

for(int i=0;i<a.length;i++){

System.out.println(a[i]);

}

for-each loop

for(int x:a){

System.out.print(x);

}

Transfer Statements -

1. break

• Within the switch case to stop fall through
• Inside loop to break the loop execution based on some condition
• Inside labeled block to break that block execution based on some condition

for(int i=-;i<10;i++){

if(i==5)

break;

System.out.println(i);

}

2. continue

• To skip the current iteration and continue for the next iteration inside loop

for(int i=0;i<=10;i++){

if(i%2==0)

continue;

System.out.println(i);

}