17 replies to this topic

[carbon]

How to detect if a number in this case, "i" starts with any number in if statement.

 Untitled.png   4.28K   14 downloads

[TheCompBoy]

Im not sure about what you mean with this question, You want to find out if the variable i that you create in the for loop is equal to any of the numbers in the if statement?

Make a line of code to print the value of i to the console.. Thats a way of knowing if its equal to the number you want.. The if statement could use some code to execute and if it executes you will know if i went to the number you wanted.
Does this help?

[carbon]

I want to know if variable (n) I create before starts with any number in if statement.

[TheCompBoy]

If you want to check the value of a variable outside the loop make an if statement that check for n.. I realy don't understand this..

[carbon]

I have this:

int n;

printf(".....");

scanf("%d", &n);


n=985742;


how to check if n starts with 9?

[gregwarner]

The easiest way would be to scan it as a sequence of characters [string] instead of an int and look to see if the first character == '9'.

You can still verify that it is a valid int by either rescanning it as an int using sscanf() or by checking each character with isdigit() in ctype.h.

[carbon]

Okay I got it! Thanks

[Flying Dutchman]

You could also divide n by 10 and print mod 10.

[gregwarner]

Flying Dutchman said:

You could also divide n by 10 and print mod 10.

This would give least significant digit. I think the OP was needing most significant digit. I assumed it was for an integer with an arbitrary number of digits, hence why I suggested scanning as a string.

[carbon]

Flying Dutchman said:

You could also divide n by 10 and print mod 10.

I need a first number, but with mod I cant make this.

[Flying Dutchman]

I meant within a loop of course. :P

[gregwarner]

Flying Dutchman said:

I meant within a loop of course. :P

I guessed that's what you meant, though, I think scanning characters from the front would be more computationally efficient, since it's the first character he's interested in.