Wednesday, March 28, 2012

Learning Python

I was cleaning out a flash drive and found the log I made two years ago when learning Python. I thought I'd post the first day here. Bear in mind that the only languages I knew beforehand were ActionScript and JavaScript.

2010/05/08 10:20: Started the Python tutorial. It's nice that you don't need to install anything extra. Hello world is simple but there are no parentheses. Interesting.

Friday, March 23, 2012

C/C++ loop surprises

A basic element of almost any program is a loop. Loops are a simple concept to grasp, but they can have pitfalls in some languages; here I will present one I learned about yesterday in C.
The basic for loop in C is of this form:
int n;
unsigned int i;
for (i=0; i<n; i++) {
    //do something
}
Which is pretty foolproof as long as you leave i alone inside the loop. But another type of loop is the decrementing loop. Here is a simple program that prints the numbers from 5 down to 1:

#include <stdio.h>


int main (int argc, char **argv) {
int n = 5;
unsigned int i;
for (i=n; i>=1; i--) {
printf("%u\n", i);
}
}
And the output:

5
4
3
2
1