The for structure
We go back to lists with the for loop, the goal of which being to set one
by one into a variable, each element of a list or a range of values.
The syntax is :
for declaration in (identifier | interval) (instructions)* /for
That means for:
- for a variable x, scanning the identifier or the interval,
- zéro, one or several instructions,
- end of structure (and next element pointed out).
Example, we have an array "a".
for text t in a ... instructions ... /for
The for loop can contains other control structures.
Embedding for: | for
text t in a for int i in 1..3 print t, i /for /for |
For structure on a single line
The compiler recognizes the end of the heading by the end of line. An instruction may be put also on the line providing the heading is terminated by a colon ":".
for text t in a : print t /for
The /for may be put also on the same line, providing a single instruction is in the bloc and it is terminated by a semi-colon.
for text in a : print t; /for
These conventions concern also if and all other control structures.
Using for on an interval. | array
a = array() for int i in 1..3 a[i] = i /for a.display() |
Displays: | >
array ( 1, 2, 3 ) |
Exercises |
1) Fill an array named "alphabet" with letters of the alphabet. |