#### `switch` statement to match a text line
While outputing to the standard stream, it is also possible to
use `switch` statement to **match a text line to a text line in a
file.** I personally think it improve readability and
maintainability in some applications.
```
import std;
void main(){
foreach (line; File("example.txt").byLine(No.keepTerminator,
"\r\n")){
switch(line) {
case " HelloWorld" :
writeln("|"~line~"|");
writeln("^This Line is here.");
break;
default :
writeln("|"~line~"|");
}
}
}
```
#### Reading file, matching line, changing the line, outputting
to both: to a standard stream and another file; line by line
In this snippet, we are not only reading a file, editing its
output and outputting to the standard output stream, but also try
to save changes on another file: filling it with the edited
output.
```
import std;
void main(){
File edit = File("example2.txt", "w");
foreach (line; File("example.txt").byLine(No.keepTerminator,
"\r\n")){
switch(line) {
case " HelloWorld":
edit.write("RandomWord\n");
writeln("|"~"RandomWord"~"|");
break;
default :
edit.write(line ~ "\n");
writeln("|" ~ line ~ "|");
}
}
edit.close;
}
```
**Inputs:**
**Example.txt**
```
test
s
HelloWorld
t
ff
```
**Outputs:**
**stdout:**
```
|test|
| s|
| |
|RandomWord|
|t|
|ff|
```
**Example2.txt**
```
test
s
RandomWord
t
ff
```
