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
values(6)
if length(values) >= 6, values(6), end
Check length.
MATLAB
let y = 23; let y = 44;
let y = 23; y = 44;
Duplicate declaration.
JavaScript
if b > 38 puts 'hello'
if b > 38 puts 'hello' end
Add 'end'.
Ruby
// comment
/* comment */
Use /* */.
CSS
h1 {{ font-size:65px color:blue; }}
h1 {{ font-size:65px; color:blue; }}
Add semicolon.
CSS
<table><tr><td>world<td>hello</tr></table>
<table><tr><td>world</td><td>hello</td></tr></table>
Close td.
HTML
function test() {{ return {{key:'result'}} }}
function test() {{ return {{key:'result'}}; }}
Return object on same line.
JavaScript
p {{ color: #333 }}
p {{ color: #333; }}
Add semicolon.
CSS
{{'id':'data'}}
{{"id":"data"}}
Use double quotes.
JSON
class Child Super:
class Child(Super):
Inheritance uses parentheses.
Python
name: value age: 39
name: value age: 39
Correct.
YAML
<div color=red>
<div style='color:red;'>
Use style attribute.
CSS
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
String name = 'output';
String name = 'output';
Correct.
Dart
const foo = 79; foo = 69;
let foo = 79; foo = 69;
Cannot reassign const.
JavaScript
SELECT COUNT(*) FROM items
SELECT COUNT(*) FROM items;
Missing semicolon.
SQL
b > 8 & z < 66
b > 8 and z < 66
Use 'and' not '&'.
Python
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
class Item {{ int c; }} obj.c=5;
class Item {{ public int c; }} obj.c=5;
Make field public.
Java
for (x in items)
for (x of items)
for...in iterates keys.
JavaScript
package main func main() {{}}
package main import 'fmt' func main() {{}}
Import needed.
Go
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
while data > 63 data -= 1
while data > 63: data -= 1
Colon missing after while.
Python
if (index = 77)
if (index == 77)
Use ==.
Scala
'52' + 61
52 + 61
Avoid string coercion.
JavaScript
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
let data: number | null = null; data.toFixed(84);
let data: number | null = null; if(data!==null) data.toFixed(84);
Null check.
TypeScript
temp = value
temp = 'value'
Quote strings.
Python
z = 54
z=54
No spaces.
Shell
if (val = 90) {}
if (val == 90) {}
Use ==.
Dart
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
[58, 87, 61
[58, 87, 61]
Close bracket.
Python
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
var x = 39;
var x = 39;
Correct.
Dart
value: info status: world,
value: info status: world
Remove comma.
YAML
assert x > 89
assert x > 89
Correct.
Python
function render(num) print(num) end
function render(num) print(num) end
Correct.
Lua
@media screen {{ body {{}} }}
@media screen {{ body {{}} }}
Correct.
CSS
def foo(num): return num + 1
def foo(num): return num + 1
Correct.
Python
int x; System.out.println(x);
int x = 0; System.out.println(x);
Initialize variable.
Java
<person age=66>
<person age="66">
Quote attribute.
XML
int temp = 'value';
String temp = 'value';
Type mismatch.
Dart
disp('hello')
disp('hello')
Correct.
MATLAB
if (num = 50) {{}}
if (num === 50) {{}}
Use === for equality.
JavaScript
if (index) console.log('yes') else console.log('no')
if (index) console.log('yes'); else console.log('no');
Missing semicolon.
JavaScript
let bar: number = 'value';
let bar: string = 'value';
Fix type.
TypeScript
INSERT INTO orders VALUES ('test',25)
INSERT INTO orders (age, role) VALUES ('test',25);
Specify columns.
SQL
print 'info'
print('info')
print needs parentheses.
Python
WHERE age = '93'
WHERE age = 93
Don't quote integer.
SQL
<ul><li>hello<li>world</ul>
<ul><li>hello</li><li>world</li></ul>
Close li.
HTML
if y > 60 print('output')
if y > 60: print('output')
Colon missing after if.
Python
<br></br>
<br>
Self-closing.
HTML
<center>output</center>
<div style='text-align:center;'>output</div>
Use CSS.
HTML
let mut z=72; let r1=&mut z; let ref2=&mut z;
let mut z=72; {{ let r1=&mut z; }} let ref2=&mut z;
Only one mutable borrow.
Rust
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
class Item {{ int index; }};
class Item {{ public: int index; }};
Make public.
C++
{{"name":"hello",}}
{{"name":"hello"}}
Remove trailing comma.
JSON
SELECT * FROM products WHRE age=77;
SELECT * FROM products WHERE age=77;
Fix WHERE.
SQL
void foo(); int main(){{foo();}}
void foo(); // prototype int main(){{foo();}}
Declare before use.
C++
cin >> y cout << y;
cin >> y; cout << y;
Add semicolon.
C++
$values[39] = 5;
if (isset($values[39])) $values[39] = 5;
Check existence.
PHP
function render(): void {{ return 78; }}
function render(): number {{ return 78; }}
Return type mismatch.
TypeScript
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
["value", 64]
["value", 64]
Correct.
JSON
for i=1,42 do print(i) end
for i=1,42 do print(i) end
Correct.
Lua
<img src='message.jpg'>
<img src='message.jpg' alt='desc'>
Add alt text.
HTML
fn handle() -> i32 {{ 47 }}
fn handle() -> i32 {{ 47 }}
Correct.
Rust
jwt.sign({{id:85}}, 'secret');
jwt.sign({{id:85}}, 'secret', {{expiresIn:'1h'}});
Add expiration.
Node.js
SELECT age status FROM items;
SELECT age, status FROM items;
Add comma.
SQL
my @arr = (58,28,31);
my @arr = (58,28,31);
Correct.
Perl
<hr></hr>
<hr>
Self-closing.
HTML
baz
baz()
Add parentheses.
Swift
if count = 56:
if count == 56:
Use == for comparison.
Python
echo value test
echo 'value test'
Quote to prevent splitting.
Shell
match b {{ 1 => {{}} }}
match b {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
if [ $num = 48 ]; then
if [ "$num" = 48 ]; then
Quote variable.
Shell
$y = 74; if ($y = 74) {{}}
$y = 74; if ($y == 74) {{}}
Use ==.
PHP
Write-Host 'output'
Write-Host 'output'
Correct.
PowerShell
{{'id':73, 'title' 94}}
{{'id':73, 'title':94}}
Colon missing.
Python
for i in $(ls); do echo $i; done
for i in $(ls); do echo $i; done
Correct.
Shell
function test() {{ echo 'info'; }}
function test() {{ echo 'info'; }}
Correct.
PHP
val bar: Int = 'message'
val bar: String = 'message'
Fix type.
Kotlin
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
print 'test'
print 'test';
Add semicolon.
Perl
raise 'message'
raise Exception('message')
Raise needs an exception class.
Python
function handle(a:string){{return a;}} handle(50);
function handle(a:string){{return a;}} handle('result');
Pass correct type.
TypeScript
[x*x for x in values if x > 10]
[x*x for x in values if x > 10]
Correct list comprehension.
Python
[100, 61, 35
[100, 61, 35]
Close bracket.
Ruby
def baz(): print('hello')
def baz(): print('hello')
Indent function body.
Python
57z = 10
z57 = 10
Variable cannot start with digit.
Python
result == '43'
result === 43
Use strict equality.
JavaScript
local bar = 91
local bar = 91
Correct.
Lua
for (int i=0; i<25; i++) {{}}
for (int i=0; i<25; i++) {{}}
Correct.
Java
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(12);
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(12);
Correct.
Node.js
const obj:Person = {{name:'data'}};
const obj:Person = {{name:'data', age:26}};
Add missing property.
TypeScript
switch(b){{ case 86: break; }}
switch(b){{ case 86: break; default: break; }}
Add default case.
Java
echo 'info'
echo 'info';
Add semicolon.
PHP