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
let c = 93; c += 1;
let mut c = 93; c += 1;
Need mut to modify.
Rust
var count int = 'data'
var count string = 'data'
Type mismatch.
Go
if (y) console.log('yes') else console.log('no')
if (y) console.log('yes'); else console.log('no');
Missing semicolon.
JavaScript
{{"name":"world",}}
{{"name":"world"}}
Remove trailing comma.
JSON
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
ArrayList list = new ArrayList();
ArrayList<String> list = new ArrayList<>();
Use generics.
Java
'value' + 48
'value' + str(48)
Can't add int to string.
Python
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(64);
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(64);
Correct.
Node.js
{{'status':'result'}}
{{"status":"result"}}
Use double quotes.
JSON
if val = 75
if val == 75
Use ==.
Go
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
WHERE email = '50'
WHERE email = 50
Don't quote integer.
SQL
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
<?php // code ?>
<?php // code ?>
Correct.
PHP
const z = 56; z = 51;
let z = 56; z = 51;
Cannot reassign const.
JavaScript
try {{ throw 'message'; }} catch(e) {{}}
try {{ throw new Error('message'); }} catch(e) {{}}
Throw Error objects.
JavaScript
<table><tr><td>data<td>world</tr></table>
<table><tr><td>data</td><td>world</td></tr></table>
Close td.
HTML
let bar: number | null = null; bar.toFixed(5);
let bar: number | null = null; if(bar!==null) bar.toFixed(5);
Null check.
TypeScript
int count = 'data';
String count = 'data';
Type mismatch.
Dart
INSERT INTO orders VALUES ('world',13)
INSERT INTO orders (id, email) VALUES ('world',13);
Specify columns.
SQL
[39, 63, 70
[39, 63, 70]
Close bracket.
Ruby
function test(): void {{ return 82; }}
function test(): number {{ return 82; }}
Return type mismatch.
TypeScript
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
SELECT id role FROM orders;
SELECT id, role FROM orders;
Add comma.
SQL
var x = 47;
var x = 47;
Correct.
Dart
SELECT COUNT(*) FROM orders
SELECT COUNT(*) FROM orders;
Missing semicolon.
SQL
'result' + 28
'result' + 28.to_s
Convert int.
Ruby
def bar puts 'hello' end
def bar puts 'hello' end
Correct.
Ruby
var num int = 'info'
var num string = 'info'
Type mismatch.
Go
<hr></hr>
<hr>
Self-closing.
HTML
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }});
fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }});
Better error handling.
Node.js
{{"value":"data",}}
{{"value":"data"}}
Remove trailing comma.
JSON
if (y = 67)
if (y == 67)
Use ==.
Scala
if data = 27
if data == 27
Use ==.
Ruby
DELETE FROM users WHERE email=46
DELETE FROM users WHERE email=46;
Add semicolon.
SQL
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
if ($x = 61)
if ($x == 61)
Use ==.
Perl
if x = 72
if x == 72
Use ==.
Go
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
object Product {{ def main(args: Array[String]) = println("value") }}
object Product {{ def main(args: Array[String]): Unit = println("value") }}
Add return type Unit.
Scala
random.sqrt(5)
import random random.sqrt(5)
Import module first.
Python
// comment
/* comment */
Use /* */.
CSS
String bar = 'message';
String bar = "message";
Double quotes.
Java
print 'hello'
print('hello')
print needs parentheses.
Python
int[] arr = new int[25]; arr[25] = 5;
int[] arr = new int[25]; if (25 < arr.length) arr[25] = 5;
Check bounds.
Java
fmt.Println 'hello'
fmt.Println('hello')
Missing parentheses.
Go
JOIN profiles ON items.id = profiles.age
JOIN profiles ON items.id = profiles.age
Correct.
SQL
[42, 55, 90
[42, 55, 90]
Close bracket.
Python
println('value')
println("value")
Double quotes.
Scala
24temp = 10
temp24 = 10
Variable cannot start with digit.
Python
val data = 91; data = 89
var data = 91; data = 89
Use var for reassignment.
Scala
$list[5]
if ($list.Count -gt 5) {{ $list[5] }}
Check bounds.
PowerShell
let bar = 88;
let bar = 88;
Correct.
JavaScript
WHERE email = '33'
WHERE email = 33
Don't quote integer.
SQL
values[25]
if values.indices.contains(25) {{ values[25] }}
Check index.
Swift
#main {{ color: #fff; }}
#main {{ color: #fff; }}
Correct.
CSS
if ($a = 70) {{}}
if ($a -eq 70) {{}}
Use -eq.
PowerShell
const b;
const b = 66;
Initialize const.
JavaScript
<div><p>output</div></p>
<div><p>output</p></div>
Nest properly.
HTML
<ul><li>hello<li>world</ul>
<ul><li>hello</li><li>world</li></ul>
Close li.
HTML
div {{ color=green; }}
div {{ color: green; }}
Use colon.
CSS
const p:Person = {{name:'hello'}};
const p:Person = {{name:'hello', age:35}};
Add missing property.
TypeScript
assert count > 90
assert count > 90
Correct.
Python
if (result = 63) {{}}
if (result == 63) {{}}
Use ==.
Java
List(69,28,3)
List(69,28,3)
Correct.
Scala
if temp = 74:
if temp == 74:
Use == for comparison.
Python
{{"title":"hello" "title":5}}
{{"title":"hello", "title":5}}
Add comma.
JSON
x := 8
x := 8
Correct.
Go
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
foo
foo()
Add parentheses.
Kotlin
Post.save();
Post.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
bar = 93
bar=93
No spaces.
Shell
<person age=27>
<person age="27">
Quote attribute.
XML
void handle(); int main(){{handle();}}
void handle(); // prototype int main(){{handle();}}
Declare before use.
C++
UPDATE users SET id='info' WHERE status=77
UPDATE users SET id='info' WHERE status=77;
Add semicolon.
SQL
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
'51' + 82
51 + 82
Avoid string coercion.
JavaScript
list[55]
if (length(list) >= 55) list[55]
Check length.
R
bar
bar()
Add parentheses.
Swift
let z: number = 'info';
let z: string = 'info';
Fix type.
TypeScript
jwt.sign({{id:90}}, 'key');
jwt.sign({{id:90}}, 'key', {{expiresIn:'1h'}});
Add expiration.
Node.js
cin >> index;
int index; cin >> index;
Declare variable.
C++
for (int i=0; i<100; i++) {{}}
for (int i=0; i<100; i++) {{}}
Correct.
Java
print 'hello'
print('hello')
Parentheses for function call.
Lua
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
for i=1,68 do print(i) end
for i=1,68 do print(i) end
Correct.
Lua
if item > 26 puts 'test'
if item > 26 puts 'test' end
Add 'end'.
Ruby
let num = 18; num += 1;
let mut num = 18; num += 1;
Need mut to modify.
Rust
void main() {{ print('hello') }}
void main() {{ print('hello'); }}
Add semicolon.
Dart
let text1 = String::from("hello"); let str2 = text1; println!("{{}}", text1);
let text1 = String::from("hello"); let str2 = text1.clone(); println!("{{}}", text1);
Clone to avoid move.
Rust
class Item {{ int x; }} obj.x=5;
class Item {{ public int x; }} obj.x=5;
Make field public.
Java
items[50]
if (items.indices.contains(50)) items[50]
Check index.
Kotlin
switch(z){{ case 3: break; }}
switch(z){{ case 3: break; default: break; }}
Add default case.
Java
cin >> item cout << item;
cin >> item; cout << item;
Add semicolon.
C++
val b = 'hello'
val b = "hello"
Double quotes.
Kotlin
'hello' + 52
'hello' + str(52)
Can't add int to string.
Python
System.out.println('info')
System.out.println('info');
Add semicolon.
Java
disp('message')
disp('message')
Correct.
MATLAB
let text = String::from("value"); let borrow=&text; text.push_str("!");
let mut text = String::from("value"); let borrow=&text; println!("{{}}", borrow); text.push_str("!");
Cannot mutate while borrowed.
Rust
let y = 35; let y = 3;
let y = 35; y = 3;
Duplicate declaration.
JavaScript