Re: how stdin stream works?
On Thursday, 20 August 2020 at 19:13:31 UTC, Ali Çehreli wrote:
On 8/19/20 11:46 AM, Flade wrote:
[...]
Thanks Steve! I will get the input a string then as you said
and then I'll try to convert it! Thanks a lot, have a nice day!
In some cases clearerr() and readln() may be what is needed:
import std.stdio;
void main() {
int x;
bool accepted = false;
while (!accepted) {
try {
write("x: ");
readf(" %d", x);
accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
stdin.clearerr();
stdin.readln();
}
}
writeln("x is ", x);
}
Note that I used " %d" because "%d/n" would not clean when
nothing was input by just hitting the Enter key. A space
character in the format string means "read and ignore any
whitespace at this point" and I like it. :)
Also note I changed the name of the variable as 'accepted'. :)
Ali
Wait! Oh man I just checked your name I'm currently reading
your book and I wanted to say that you did an EXCELLENT work and
I love it! Thanks a lot! You are great!!!
Re: how stdin stream works?
On Thursday, 20 August 2020 at 19:13:31 UTC, Ali Çehreli wrote:
On 8/19/20 11:46 AM, Flade wrote:
[...]
In some cases clearerr() and readln() may be what is needed:
import std.stdio;
void main() {
int x;
bool accepted = false;
while (!accepted) {
try {
write("x: ");
readf(" %d", x);
accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
stdin.clearerr();
stdin.readln();
}
}
writeln("x is ", x);
}
Note that I used " %d" because "%d/n" would not clean when
nothing was input by just hitting the Enter key. A space
character in the format string means "read and ignore any
whitespace at this point" and I like it. :)
Also note I changed the name of the variable as 'accepted'. :)
Ali
Thanks a lot! Very useful info!!! And sorry for answering so
late, I wasn't expecting someone to answer so I wasn't checking.
Have a great day my friend!
Re: how stdin stream works?
On 8/19/20 11:46 AM, Flade wrote:
Try instead getting a line via readln, and then trying to read that
into your expected input.
-Steve
Thanks Steve! I will get the input a string then as you said and then
I'll try to convert it! Thanks a lot, have a nice day!
In some cases clearerr() and readln() may be what is needed:
import std.stdio;
void main() {
int x;
bool accepted = false;
while (!accepted) {
try {
write("x: ");
readf(" %d", x);
accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
stdin.clearerr();
stdin.readln();
}
}
writeln("x is ", x);
}
Note that I used " %d" because "%d/n" would not clean when nothing was
input by just hitting the Enter key. A space character in the format
string means "read and ignore any whitespace at this point" and I like
it. :)
Also note I changed the name of the variable as 'accepted'. :)
Ali
Re: how stdin stream works?
On Wednesday, 19 August 2020 at 18:11:23 UTC, Steven
Schveighoffer wrote:
On 8/19/20 1:44 PM, Flade wrote:
Hi everyone! I'm trying to do error handling (with the try
block) and when I give a wrong value to the variable (it is an
integer and I give a non-number value), then It doesn't let me
re get input. The code:
int x;
bool not_accepted = false;
while (!not_accepted) {
try {
write("x: ");
readf("%d\n", x);
not_accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
}
Probably readf stops as soon as it encounters an error, meaning
that your input is still present.
Try instead getting a line via readln, and then trying to read
that into your expected input.
-Steve
Thanks Steve! I will get the input a string then as you said and
then I'll try to convert it! Thanks a lot, have a nice day!
Re: how stdin stream works?
On 8/19/20 1:44 PM, Flade wrote:
Hi everyone! I'm trying to do error handling (with the try block) and
when I give a wrong value to the variable (it is an integer and I give a
non-number value), then It doesn't let me re get input. The code:
int x;
bool not_accepted = false;
while (!not_accepted) {
try {
write("x: ");
readf("%d\n", x);
not_accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
}
Probably readf stops as soon as it encounters an error, meaning that
your input is still present.
Try instead getting a line via readln, and then trying to read that into
your expected input.
-Steve
how stdin stream works?
Hi everyone! I'm trying to do error handling (with the try block)
and when I give a wrong value to the variable (it is an integer
and I give a non-number value), then It doesn't let me re get
input. The code:
int x;
bool not_accepted = false;
while (!not_accepted) {
try {
write("x: ");
readf("%d\n", x);
not_accepted = true;
} catch (Exception msg) {
writeln("Please give a right coordinate");
}
