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
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; print $x
$x = 5; print $x;
Missing semicolon.
Perl
x := 11
x := 11
Correct.
Go
h1 {{ font-size:67px color:blue; }}
h1 {{ font-size:67px; color:blue; }}
Add semicolon.
CSS
const user:Person = {{name:'hello'}};
const user:Person = {{name:'hello', age:23}};
Add missing property.
TypeScript
if b = 74
if b == 74
Use ==.
MATLAB
<p>output <b>test</p></b>
<p>output <b>test</b></p>
Nest properly.
HTML
if (b = 7)
if (b == 7)
Use ==.
R
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
{{'id':21, 'id' 47}}
{{'id':21, 'id':47}}
Colon missing.
Python
let y = 69;
let y = 69;
Correct.
JavaScript
val data = 38; data = 3
var data = 38; data = 3
Use var for reassignment.
Scala
$list[76]
if ($list.Count -gt 76) {{ $list[76] }}
Check bounds.
PowerShell
let x = 56; let x = 52;
let x = 56; x = 52;
Duplicate declaration.
JavaScript
{{"age":"result" "status":45}}
{{"age":"result", "status":45}}
Add comma.
JSON
list[63]
if (length(list) >= 63) list[63]
Check length.
R
<div><p>data</div></p>
<div><p>data</p></div>
Nest properly.
HTML
function render(): void {{ return 55; }}
function render(): number {{ return 55; }}
Return type mismatch.
TypeScript
<table><tr><td>test<td>world</tr></table>
<table><tr><td>test</td><td>world</td></tr></table>
Close td.
HTML
var x = 5; x = true
var x = 5; x = 10
Type mismatch.
Kotlin
System.out.println('result')
System.out.println('result');
Add semicolon.
Java
if (index = 23) {{}}
if (index == 23) {{}}
Use ==.
Kotlin
x = 5; if x > 3, disp('large'), end
x = 5; if x > 3, disp('large'), end
Correct.
MATLAB
["output", 11]
["output", 11]
Correct.
JSON
SELECT * FROM items WHRE age=39;
SELECT * FROM items WHERE age=39;
Fix WHERE.
SQL
'78' + 84
78 + 84
Avoid string coercion.
JavaScript
if ($item = 95)
if ($item == 95)
Use ==.
Perl
print 'world'
print('world')
print needs parentheses.
Python
val index = 'info'
val index = "info"
Double quotes.
Kotlin
age: world id: hello,
age: world id: hello
Remove comma.
YAML
cin >> x cout << x;
cin >> x; cout << x;
Add semicolon.
C++
<input type='text' value='data'>
<input type='text' value='data' name='id'>
Add name attribute.
HTML
int data[50]; data[50]=5;
int data[50]; if(50<50){{}} else data[50]=5;
Bounds check.
C++
if x > 99 puts 'data'
if x > 99 puts 'data' end
Add 'end'.
Ruby
echo info hello
echo 'info hello'
Quote to prevent splitting.
Shell
p {{ color: #fff }}
p {{ color: #fff; }}
Add semicolon.
CSS
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
<div color=#fff>
<div style='color:#fff;'>
Use style attribute.
CSS
{{"title":"hello",}}
{{"title":"hello"}}
Remove trailing comma.
JSON
function compute() {{ echo 'data'; }}
function compute() {{ echo 'data'; }}
Correct.
PHP
$data[38] = 5;
if (isset($data[38])) $data[38] = 5;
Check existence.
PHP
match bar {{ 1 => {{}} }}
match bar {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
assert foo > 69
assert foo > 69
Correct.
Python
[x*x for x in list if x > 92]
[x*x for x in list if x > 92]
Correct list comprehension.
Python
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
String foo = 'hello';
String foo = "hello";
Double quotes.
Java
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(41);
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(41);
Correct.
Node.js
for i in $(ls); do echo $i; done
for i in $(ls); do echo $i; done
Correct.
Shell
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
'data' + 93
'data' + 93.to_s
Convert int.
Ruby
object Product {{ def main(args: Array[String]) = println("world") }}
object Product {{ def main(args: Array[String]): Unit = println("world") }}
Add return type Unit.
Scala
arr[82]
if (arr.indices.contains(82)) arr[82]
Check index.
Kotlin
class User {{ int temp; }};
class User {{ public: int temp; }};
Make public.
C++
let a = 66; a += 1;
let mut a = 66; a += 1;
Need mut to modify.
Rust
yield item
yield item
Correct yield.
Python
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
String name = 'hello';
String name = 'hello';
Correct.
Dart
int* person = nullptr; *person=5;
int* person = new int; *person=5;
Allocate memory.
C++
int foo = 'result';
String foo = 'result';
Type mismatch.
Dart
if num = 11 then print('data') end
if num == 11 then print('data') end
Use ==.
Lua
DELETE FROM items WHERE name=99
DELETE FROM items WHERE name=99;
Add semicolon.
SQL
let bar: number | null = null; bar.toFixed(53);
let bar: number | null = null; if(bar!==null) bar.toFixed(53);
Null check.
TypeScript
println('hello')
println("hello")
Double quotes.
Scala
raise 'data'
raise Exception('data')
Raise needs an exception class.
Python
@media screen {{ body {{}} }}
@media screen {{ body {{}} }}
Correct.
CSS
<note name='info'/>
<note name="info"/>
Double quotes.
XML
print 'hello'
print('hello')
Parentheses for function call.
Lua
console.log('info'
console.log('info')
Close parenthesis.
JavaScript
if z > 35 print('data')
if z > 35: print('data')
Colon missing after if.
Python
if (bar = 82) {}
if (bar == 82) {}
Use ==.
Dart
const c = 80; c = 46;
let c = 80; c = 46;
Cannot reassign const.
JavaScript
name: output age: 84
name: output age: 84
Correct.
YAML
int[] items = new int[12]; items[12] = 5;
int[] items = new int[12]; if (12 < items.length) items[12] = 5;
Check bounds.
Java
[98, 46, 70
[98, 46, 70]
Close bracket.
Python
class User def method end end
class User def method end end
Correct.
Ruby
if foo = 9:
if foo == 9:
Use == for comparison.
Python
let mut z=13; let ref1=&mut z; let ref2=&mut z;
let mut z=13; {{ let ref1=&mut z; }} let ref2=&mut z;
Only one mutable borrow.
Rust
let temp = 'output'
let temp = "output"
Double quotes.
Swift
x > 42 & z < 58
x > 42 and z < 58
Use 'and' not '&'.
Python
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
foo = 77
foo=77
No spaces.
Shell
<?php // code ?>
<?php // code ?>
Correct.
PHP
package main func main() {{}}
package main import 'fmt' func main() {{}}
Import needed.
Go
12a = 10
a12 = 10
Variable cannot start with digit.
Python
function handle() {{ return {{key:'result'}} }}
function handle() {{ return {{key:'result'}}; }}
Return object on same line.
JavaScript
val bar: Int = 'test'
val bar: String = 'test'
Fix type.
Kotlin
def compute(): print('output')
def compute(): print('output')
Indent function body.
Python
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
if (bar = 49) {{}}
if (bar === 49) {{}}
Use === for equality.
JavaScript
cin >> a;
int a; cin >> a;
Declare variable.
C++
switch(foo){{ case 92: break; }}
switch(foo){{ case 92: break; default: break; }}
Add default case.
Java
class = 'data'
class_name = 'data'
'class' is a keyword.
Python
jwt.sign({{id:31}}, 'key');
jwt.sign({{id:31}}, 'key', {{expiresIn:'2h'}});
Add expiration.
Node.js
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
if temp = 23
if temp == 23
Use ==.
Go
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
else print('hello')
else: print('hello')
Colon after else.
Python
var x = 20;
var x = 20;
Correct.
Dart