HELP > Printing String Gradually!

[Inneart]

Hi Folks,

I'm an undergrad at National University of Singapore. Just have a slight trouble with my current assignment.

How do you gradually print a string say "ABCDEFGH", and you want it to print like:



A
AB
ABC
ABCD
ABCDE
ABCDEF
ABCDEFG
ABCDEFGH



Many thanks!!

[laserlight]

I'm not going to hand out code on a silver platter just because you're from my alma mater

Start by writing a program that given a string such as "ABCDEFGH", prints the first n characters of the string, where n is some suitable number, e.g., 3. Now, think of how you can write a loop to vary n from 1 to the number of characters in the string.

[Inneart]

I'm not going to hand out code on a silver platter just because you're from my alma mater

Start by writing a program that given a string such as "ABCDEFGH", prints the first n characters of the string, where n is some suitable number, e.g., 3. Now, think of how you can write a loop to vary n from 1 to the number of characters in the string.

I already thought of a simple loop:

for(i=0; i<strlen(text); i++)
{
   printf("%s\n", text[i]);
}

But it doesn't work.

HELP!

[laserlight]

If you change %s to %c, that should work, except that it would only print the entire input string. As I implied earlier, you should use nested loops.

[Inneart]

If you change %s to %c, that should work, except that it would only print the entire input string. As I implied earlier, you should use nested loops.

Mhmm... 2 loops...

for(i=0; i<strlen(text); i++)
{
   for(j=0; j<strlen(text); j++)
   {
      printf("%c\n", text[j])
    }
}

This gives me

[code]
A
B
C
D
E
F
G
A
B
C
D
E
F
G
.
.
.
.
etc

The issue that I have is, I have no idea how do I print A, then AB, then ABC. And my string could be say, a 100 long scary string. Z.

[laserlight]

The issue that I have is, I have no idea how do I print A, then AB, then ABC.

You're close. You don't have to use strlen(text) in both loops, and you do not have to print a newline immediately after printing each character. (Actually, you should save the result of strlen(text) and use it just once, but details of the reason behind this will be covered in CS1102.)

[Inneart]

You're close. You don't have to use strlen(text) in both loops, and you do not have to print a newline immediately after printing each character. (Actually, you should save the result of strlen(text) and use it just once, but details of the reason behind this will be covered in CS1102.)

Is this it? Hehe.

for(i=0; i<strlen(text)+1; i++)
{
  for(j=0; j<i; j++)
  {
     printf("%c", text[j]);
   }
  printf("\n");
}

[laserlight]

Almost. i should begin from 1 instead of 0, and then instead of adding 1 to strlen(text), just use <= to compare.

[Inneart]

Almost. i should begin from 1 instead of 0, and then instead of adding 1 to strlen(text), just use <= to compare.

Thanks laserlight. You are a great help. Bet you got A+ for all your programming modules. Thanks a mil!

[CommonTater]

Getting closer... it's in the way you end your loops...

for(i=0; i<strlen(text); i++)
     { for(j=0; j<i; j++)
          printf("%c", text[j]);
        printf("\n"); }

[laserlight]

Yeah, CommonTater's idea should also work, but I think that it is more intuitive to change the outer loop with the idea that it controls the number of characters that you intend to print on each line.

[Adak]

if:
width was the number of your letters to be printed.

i was the number of char's you had printed on any one row.

j was the number of char's you needed to print on any one row.

set j=1.

Now you're ready for your two nested loops:

1) do loop while incremented j is less than width - the outer loop
2) inner for i equal 0 i less than j increment i - the inner loop

It's very intuitive, short and draws beautifully. Doesn't matter how many letters there are. Just set width variable to what you want.


Here, I used it to print just one char: @ printing different char's is also easy though.

@
@@
@@@
@@@@
@@@@@
@@@@@@
@@@@@@@
@@@@@@@@
@@@@@@@@@
@@@@@@@@@@
@@@@@@@@@@@

			    press enter when ready

[Inneart]

Thanks guys. Really appreciated it.

[nonoob]

char *text = "ABCDEFGH";

for (i = 1; i <= strlen(text); i++)
    printf("%.*s\n", i, text);