cpp/pointers/reset

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Description
html markup
shown to student

In a previous exercise we tried to write a function that would
reset a variable, but it failed to work because of C++'s pass-by-value
semantics.
<p>We can fix it now! Use pointers to do so.

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Engine
Choices
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Correct answer
Template / Reference solution

Template / Reference solution

#include <iostream>
using namespace std;

void reset(\[int* x\show:int x]\)
{
\[
*x = 0;
\show:
x = 0;
]\
}

int main() {
int num = 103;
reset(\[&num\show:num]\);
cout << num;
}

Java test suite
See manual

C++ test suite
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e.g. [{"stdin":"hi", "args":["4", "5"]}, {"stdin":"noargs"}]
to just run once with no input use [{}]

[
{}
]

C++ test suite
See manual

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Property	Value
Description html markup shown to student	In a previous exercise we tried to write a function that would reset a variable, but it failed to work because of C++'s pass-by-value semantics. <p>We can fix it now! Use pointers to do so.
Epilogue html markup shown when solved	remove
Public permissions	remove
Remarks Comments, history, license, etc.	remove
Engine
Choices json list of string, bool pairs e.g. `[["good", true], ["bad", false]]`
Correct answer
Template / Reference solution
Template / Reference solution	#include <iostream> using namespace std; void reset(\[int* x\show:int x]\) { \[ *x = 0; \show: x = 0; ]\ } int main() { int num = 103; reset(\[&num\show:num]\); cout << num; }
Java test suite See manual
C++ test suite json list of stdin/args tests e.g. `[{"stdin":"hi", "args":["4", "5"]}, {"stdin":"noargs"}]` to just run once with no input use `[{}]`	[ {} ]
C++ test suite See manual
Forbidden substrings json list of strings e.g. `["for","while"]`	remove
Solution visibility	remove
Java imports json list of importables e.g. `["java.util.*"]`	remove
Override Java classname else defaults to websheet name	remove
Dependent on other websheets? json list of websheet names in this folder e.g. `["DataStructure"]`	remove
Is example? i.e., just a demo	remove
Add compiler flag(s) json list of flags e.g. `["-Wno-unused-variable"]`	remove
Remove default compiler flag(s) json list of flags see default_cppflags e.g. `["-Wno-write-strings"]`	remove

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