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+--- Thread: REPLACE Doesn't. (/thread-8073.html)
REPLACE Doesn't. - toml_12953 - 03-31-2017 01:40 PM
I'm trying to replace spaces in a string with zeroes but I get the same string back unchanged. The program below prints
" 9"
" 9"
Of course I'm doing something wrong but I can't figure out what. REPLACE does work at the home screen.
Tom L
PHP Code:
EXPORT test()
BEGIN
local x,i;
print();
x:=" 9";
print(""""+x+"""");
for i from 1 to 4 do
replace(x,i,"0");
end;
print(""""+x+"""");
END;
RE: REPLACE Doesn't. - Dieter - 03-31-2017 01:48 PM
(03-31-2017 01:40 PM)toml_12953 Wrote:PHP Code:
for i from 1 to 4 do
replace(x,i,"0");
end;
This probably is a very dumb answer, as I do not even have a Prime at hand to check it. But in all programming languages I know the "replace" string function does not replace the i–th character, instead it replaces one substring by another. Like this:
replace("apple pie", "apple", "orange") => "orange pie"
So the right approach may be something like a simple replace(x," ","0"). No for-loop required.
But again: probably this is a very stupid answer. You should know since you've got the manual. ;-)
Dieter
Edit: replaced a 9 with a 0.
RE: REPLACE Doesn't. - eried - 03-31-2017 01:53 PM
You have to store the new result:
replace(x,i,"0");
change to:
x:=replace(x,i,"0");
RE: REPLACE Doesn't. - toml_12953 - 03-31-2017 02:06 PM
(03-31-2017 01:48 PM)Dieter Wrote:(03-31-2017 01:40 PM)toml_12953 Wrote:PHP Code:
for i from 1 to 4 do
replace(x,i,"0");
end;
This probably is a very dumb answer, as I do not even have a Prime at hand to check it. But in all programming languages I know the "replace" string function does not replace the i–th character, instead it replaces one substring by another. Like this:
replace("apple pie", "apple", "orange") => "orange pie"
So the right approach may be something like a simple replace(x," ","9"). No for-loop required.
But again: probably this is a very stupid answer. You should know since you've got the manual. ;-)
Dieter
I tried this:
PHP Code:
x:="apple pie";
replace(x, "apple", "orange");
print(x);
"apple pie" prints. I'm really craving orange pie!
It seems to be a problem replacing characters in a variable.Tom L
RE: REPLACE Doesn't. - Han - 03-31-2017 02:10 PM
(03-31-2017 02:06 PM)toml_12953 Wrote: I tried this:
PHP Code:
x:="apple pie";
replace(x, "apple", "orange");
print(x);
"apple pie" prints. I'm really craving orange pie!
Tom L
See eried's post prior to yours; you need to save the result since the function does not modify the input in place.
RE: REPLACE Doesn't. - toml_12953 - 03-31-2017 02:15 PM
(03-31-2017 02:10 PM)Han Wrote:(03-31-2017 02:06 PM)toml_12953 Wrote: I tried this:
PHP Code:
x:="apple pie";
replace(x, "apple", "orange");
print(x);
"apple pie" prints. I'm really craving orange pie!
Tom L
See eried's post prior to yours; you need to save the result since the function does not modify the input in place.
Ah! I didn't realize that even parameters in predefined functions are passed by value. Thanks!
Tom L
RE: REPLACE Doesn't. - Tim Wessman - 03-31-2017 03:59 PM
(03-31-2017 02:15 PM)toml_12953 Wrote: Ah! I didn't realize that even parameters in predefined functions are passed by value. Thanks!
Everything in PPL is passed by value. I believe the only exception here is that when you cross into the CAS inside a program, variables are passed as variables so that the CAS can do what it needs with them.
RE: REPLACE Doesn't. - Dieter - 03-31-2017 05:25 PM
(03-31-2017 02:15 PM)toml_12953 Wrote: Ah! I didn't realize that even parameters in predefined functions are passed by value.
Does this mean that this...
Code:
x:="apple pie";
x:=replace(x, "apple", "orange");
print(x);...actually works on the Prime?
And what about your original example and x:=replace(x, " ", "0") then?
Dieter,
just curious. ;-)
RE: REPLACE Doesn't. - toml_12953 - 04-01-2017 12:25 AM
(03-31-2017 05:25 PM)Dieter Wrote:(03-31-2017 02:15 PM)toml_12953 Wrote: Ah! I didn't realize that even parameters in predefined functions are passed by value.
Does this mean that this...
Code:
x:="apple pie";
x:=replace(x, "apple", "orange");
print(x);
...actually works on the Prime?
And what about your original example and x:=replace(x, " ", "0") then?
Dieter,
just curious. ;-)
Yes! I can now have my orange pie. and I get 00009 with that replace.
Tom L