Question

JAVA Nested for Loops
How will this work
for(a=1;a<=5;a++)
{
for(b=1;b<=a;b++)
{
System.out.print(b);
}
System.out.println();
}
Please show me the drill at every step?

Answer 1

Well look:
for(a=1;a<=5;a++){
for(b=1;b<=a;b++){
System.out.print(b); // Print the value of b
}
System.out.println(); // Return to line.
}

Step 1 : a = 1
(a <= 5) --> Yes
{ Step 1 : b = 1
(b <= 1) --> Yes
print(b) // We will print 1.
b = b + 1
Step 2 : b = 2
(b <= 1) --> No
// Exit the for loop.
}
Return to line.
a = a + 1;

The result of this first step will be as follow :
1
{Your cursor is pointing here for a New line}

Step 2 : a = 2
(a <= 5) --> Yes
{ Step 1 : b = 1
(b <= 2) --> Yes
print(b) // We will print 1.
b = b + 1
Step 2 : b = 2
(b <= 2) --> Yes
print(b) // We will print 2.
b = b + 1
Step 3 : b = 3
(b <= 2) --> No
// Exit the for loop.
}
Return to line.
a = a + 1;

The result of the first and second step will be as follow :
1
12
{Your cursor is pointing here for a New line}

And so on... so when you finish all your 5 steps, the result will be as follow :
1
12
123
1234
12345

Hope that help you, Good luck.

Answer 2

One syntax detail: a and b were never given a type in your question, so technically the code shouldn't compile. It should be:

for( int a = 1; a <= 5; a++ )
{
}

Answer 3

She is giving just a part from her program, maybe in the top she declared a and b as intergers.

Answer 4

How will this work
for(a=1;a<=5;a++)

It won't compile.

Answer 5

Its just a part of the program. a and b are integers. And @ktobah thanks for the help.

Answer 6

@leena1996 You are welcome.
@rsmith6559 It will compile well because as I said she already declared a and b in the top as integers.

Answer 7

The question was "How will this work". There's no type declaration, so it won't compile.

As you get more experienced troubleshooting, you'll learn to listen closely to the user.

Answer 8

Ok

Answer 9

This may help: http://is.gd/G3TnSf