Variable declaration reset: Difference between revisions
Added C
m (→{{header|Red}}: add some comments) |
(Added C) |
||
Line 32:
with [[Rutgers_ALGOL_68|Rutgers Algol 68]]:<br>
No output.
=={{header|C}}==
Note firstly that it's possible to create variables in C without initializing them. However, if you do so, the value the variable will contain is unpredictable and so here we give '(g)prev' an initial value of 0 to make absolutely sure it won't clash with the values in the array.
The following compiles using either C89/90 (-std=c90 -ansi -pedantic) or C99 syntax using gcc 9.4.0.
<lang c>#include <stdio.h>
int main() {
int i, gprev = 0;
int s[7] = {1, 2, 2, 3, 4, 4, 5};
/* There is no output as 'prev' is created anew each time
around the loop and set implicitly to zero. */
for (i = 0; i < 7; ++i) {
int curr = s[i];
int prev = 0;
if (i > 0 && curr == prev) printf("%d\n", i);
prev = curr;
}
/* Now 'gprev' is used and reassigned
each time around the loop producing the desired output. */
for (i = 0; i < 7; ++i) {
int curr = s[i];
if (i > 0 && curr == gprev) printf("%d\n", i);
gprev = curr
}
return 0;
}</lang>
{{out}}
<pre>
2
5
</pre>
=={{header|Factor}}==
| |||