Question

It seems like the following from the PHP manual regarding for loops is incorrect.

They behave like their C counterparts.

This is my understanding of for loops.
In C
for (i = foo; i < 10; i++) { /* body */ }
is equivalent to

if ( i = foo )  
{   while (i < 10)  
    {    /* body */
         i++;
    }
}

In PHP the comparable loop
for ($i = $foo; $i < 10; $i++) { /* body */ }
becomes

$i = $foo;
while ($i < 10)
{   /* body */
    $i++;
}

The difference is that in PHP $i = $foo is not a condition but rather a convenient place for a statement. Suppose we change the single = to ==. The distinction becomes significant. Is this correct? If so, then PHP and C loops behave differently and the manual is incorrect, right?

Answer 1

They are exactly the same, but your understanding of C’s for loops is wrong. They are the same as in PHP.

 for (x; y; z) { /* body */ }

is almost like

 x;

 while (y) {
     /* body */
     z;
 }

Though the for and while examples in C are not exactly the same because of scopes and things.