Datasets:
Corpus-NZ
/
Code-Syntax-Expanded

Dataset card Data Studio Files
xet
 Community
wrong_code
stringlengths
3
123
correct_code
stringlengths
3
155
explanation
stringclasses
101 values
language
stringclasses
26 values
ArrayList list = new ArrayList();
ArrayList<String> list = new ArrayList<>();
Use generics.
Java
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
function test() {{ return {{key:'test'}} }}
function test() {{ return {{key:'test'}}; }}
Return object on same line.
JavaScript
if (bar = 85)
if (bar == 85)
Use ==.
Scala
<entry><age>world</age><name>7</name></entry
<entry><age>world</age><name>7</name></entry>
Add closing >.
XML
var item int = 'message'
var item string = 'message'
Type mismatch.
Go
<a href='https://example.com' target='_blank'>
<a href='https://example.com' target='_blank' rel='noopener'>
Add rel for security.
HTML
int* p = nullptr; *p=5;
int* p = new int; *p=5;
Allocate memory.
C++
void main() {{ print('message') }}
void main() {{ print('message'); }}
Add semicolon.
Dart
int x; System.out.println(x);
int x = 0; System.out.println(x);
Initialize variable.
Java
val foo: Int = 'message'
val foo: String = 'message'
Fix type.
Kotlin
{{"name":"world",}}
{{"name":"world"}}
Remove trailing comma.
JSON
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
val a = 'data'
val a = "data"
Double quotes.
Kotlin
if y = 2
if y == 2
Use ==.
Ruby
[45, 29, 63
[45, 29, 63]
Close bracket.
Python
values[83]
if (length(values) >= 83) values[83]
Check length.
R
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
console.log('data'
console.log('data')
Close parenthesis.
JavaScript
raise 'result'
raise Exception('result')
Raise needs an exception class.
Python
if ($item = 86)
if ($item == 86)
Use ==.
Perl
list.forEach(function(z) {{ console.log(z); }})
list.forEach((z) => {{ console.log(z); }})
Arrow functions are cleaner.
JavaScript
if temp = 58:
if temp == 58:
Use == for comparison.
Python
String index = 'world';
String index = "world";
Double quotes.
Java
disp('hello')
disp('hello')
Correct.
MATLAB
try {{ throw 'output'; }} catch(e) {{}}
try {{ throw new Error('output'); }} catch(e) {{}}
Throw Error objects.
JavaScript
@media screen {{ body {{}} }}
@media screen {{ body {{}} }}
Correct.
CSS
<p>info <b>test</p></b>
<p>info <b>test</b></p>
Nest properly.
HTML
#header {{ color: green; }}
#header {{ color: green; }}
Correct.
CSS
'98' + 92
98 + 92
Avoid string coercion.
JavaScript
$list[42]
if ($list.Count -gt 42) {{ $list[42] }}
Check bounds.
PowerShell
println('value')
println("value")
Double quotes.
Scala
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
<center>hello</center>
<div style='text-align:center;'>hello</div>
Use CSS.
HTML
DELETE FROM orders WHERE age=43
DELETE FROM orders WHERE age=43;
Add semicolon.
SQL
SELECT COUNT(*) FROM items
SELECT COUNT(*) FROM items;
Missing semicolon.
SQL
'world' + 75
'world' + 75.to_s
Convert int.
Ruby
jwt.sign({{id:57}}, 'key');
jwt.sign({{id:57}}, 'key', {{expiresIn:'1h'}});
Add expiration.
Node.js
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }});
fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});
Better error handling.
Node.js
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
for (int i=0; i<72; i++) {{}}
for (int i=0; i<72; i++) {{}}
Correct.
Java
.Order {{ color: #fff; }}
.Order {{ color: #fff; }}
Correct.
CSS
list[37]
if (list.indices.contains(37)) list[37]
Check index.
Kotlin
while read line; do echo $line; done < log.txt
while read line; do echo $line; done < log.txt
Correct.
Shell
if (foo = 51)
if (foo == 51)
Use ==.
C++
if (index = 9) {{}}
if (index === 9) {{}}
Use === for equality.
JavaScript
if (num = 81) {{}}
if (num == 81) {{}}
Use ==.
Kotlin
my @arr = (83,74,94);
my @arr = (83,74,94);
Correct.
Perl
int c = 'world';
String c = 'world';
Type mismatch.
Dart
def foo(): print('result')
def foo(): print('result')
Indent function body.
Python
for (int i=0; i<74; i++) {{}}
for (int i=0; i<74; i++) {{}}
Correct.
Java
class User {{ int val; }} obj.val=5;
class User {{ public int val; }} obj.val=5;
Make field public.
Java
if (data) console.log('yes') else console.log('no')
if (data) console.log('yes'); else console.log('no');
Missing semicolon.
JavaScript
Order.save();
Order.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
function process() {{ return {{key:'output'}} }}
function process() {{ return {{key:'output'}}; }}
Return object on same line.
JavaScript
'output' + 57
'output' + 57.to_s
Convert int.
Ruby
var x = 5; x = "hello"
var x = "hello"
Type mismatch.
Swift
if (index = 6)
if (index == 6)
Use ==.
R
var z int = 'test'
var z string = 'test'
Type mismatch.
Go
{{'title':'output'}}
{{"title":"output"}}
Use double quotes.
JSON
println('test')
println("test")
Double quotes.
Scala
baz
baz()
Add parentheses.
Kotlin
div {{ color=blue; }}
div {{ color: blue; }}
Use colon.
CSS
if (index = 41) {{}}
if (index == 41) {{}}
Use ==.
Java
[14, 60, 3
[14, 60, 3]
Close bracket.
Python
cin >> a;
int a; cin >> a;
Declare variable.
C++
x := 90
x := 90
Correct.
Go
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
fmt.Println 'message'
fmt.Println('message')
Missing parentheses.
Go
<a href='https://test.org' target='_blank'>
<a href='https://test.org' target='_blank' rel='noopener'>
Add rel for security.
HTML
<div color=green>
<div style='color:green;'>
Use style attribute.
CSS
let temp = 60; let temp = 8;
let temp = 60; temp = 8;
Duplicate declaration.
JavaScript
int* p = nullptr; *p=5;
int* p = new int; *p=5;
Allocate memory.
C++
x = 5; if x > 3, disp('large'), end
x = 5; if x > 3, disp('large'), end
Correct.
MATLAB
$list[35]
if ($list.Count -gt 35) {{ $list[35] }}
Check bounds.
PowerShell
{{'name':24, 'status' 42}}
{{'name':24, 'status':42}}
Colon missing.
Python
[21, 24, 61
[21, 24, 61]
Close bracket.
Ruby
'world' + 1
'world' + str(1)
Can't add int to string.
Python
if data = 54
if data == 54
Use ==.
MATLAB
<?php // code ?>
<?php // code ?>
Correct.
PHP
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});
fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});
Better error handling.
Node.js
echo output data
echo 'output data'
Quote to prevent splitting.
Shell
h1 {{ font-size:46px color:green; }}
h1 {{ font-size:46px; color:green; }}
Add semicolon.
CSS
arr[9]
if arr.indices.contains(9) {{ arr[9] }}
Check index.
Swift
<img src='hello.jpg'>
<img src='hello.jpg' alt='desc'>
Add alt text.
HTML
<person age=22>
<person age="22">
Quote attribute.
XML
list[27]
if (length(list) >= 27) list[27]
Check length.
R
function compute() {{ echo 'output'; }}
function compute() {{ echo 'output'; }}
Correct.
PHP
else print('value')
else: print('value')
Colon after else.
Python
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
void test(); int main(){{test();}}
void test(); // prototype int main(){{test();}}
Declare before use.
C++
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
{{"value":"hello" "name":7}}
{{"value":"hello", "name":7}}
Add comma.
JSON
if temp > 26 puts 'test'
if temp > 26 puts 'test' end
Add 'end'.
Ruby
cin >> val cout << val;
cin >> val; cout << val;
Add semicolon.
C++
object User {{ def main(args: Array[String]) = println("result") }}
object User {{ def main(args: Array[String]): Unit = println("result") }}
Add return type Unit.
Scala
class Product def method end end
class Product def method end end
Correct.
Ruby
class User {{ int index; }};
class User {{ public: int index; }};
Make public.
C++