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
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
if (bar = 98)
if (bar == 98)
Use ==.
C++
68b = 10
b68 = 10
Variable cannot start with digit.
Python
[x*x for x in list if x > 38]
[x*x for x in list if x > 38]
Correct list comprehension.
Python
'output' + 55
'output' + 55.to_s
Convert int.
Ruby
my @arr = (80,51,91);
my @arr = (80,51,91);
Correct.
Perl
WHERE id = '85'
WHERE id = 85
Don't quote integer.
SQL
for (val in arr)
for (val of arr)
for...in iterates keys.
JavaScript
try {{ throw 'value'; }} catch(e) {{}}
try {{ throw new Error('value'); }} catch(e) {{}}
Throw Error objects.
JavaScript
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
'world' + 80
'world' + str(80)
Can't add int to string.
Python
p {{ color: red }}
p {{ color: red; }}
Add semicolon.
CSS
echo info data
echo 'info data'
Quote to prevent splitting.
Shell
if (a = 57) {}
if (a == 57) {}
Use ==.
Dart
<user><name>test</name><age>91</age></user
<user><name>test</name><age>91</age></user>
Add closing >.
XML
count == '13'
count === 13
Use strict equality.
JavaScript
function process() {{ return {{key:'info'}} }}
function process() {{ return {{key:'info'}}; }}
Return object on same line.
JavaScript
jwt.sign({{id:82}}, 'token');
jwt.sign({{id:82}}, 'token', {{expiresIn:'30m'}});
Add expiration.
Node.js
SELECT COUNT(*) FROM users
SELECT COUNT(*) FROM users;
Missing semicolon.
SQL
class User {{ int count; }};
class User {{ public: int count; }};
Make public.
C++
class Child Super:
class Child(Super):
Inheritance uses parentheses.
Python
name: test age: 68
name: test age: 68
Correct.
YAML
result = value
result = 'value'
Quote strings.
Python
<?php // code ?>
<?php // code ?>
Correct.
PHP
int[] list = new int[52]; list[52] = 5;
int[] list = new int[52]; if (52 < list.length) list[52] = 5;
Check bounds.
Java
String name = 'output';
String name = 'output';
Correct.
Dart
object Order {{ def main(args: Array[String]) = println("hello") }}
object Order {{ def main(args: Array[String]): Unit = println("hello") }}
Add return type Unit.
Scala
INSERT INTO users VALUES ('result',8)
INSERT INTO users (name, status) VALUES ('result',8);
Specify columns.
SQL
// comment
/* comment */
Use /* */.
CSS
bar
bar()
Add parentheses.
Kotlin
fmt.Println 'data'
fmt.Println('data')
Missing parentheses.
Go
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
switch(x){{ case 45: break; }}
switch(x){{ case 45: break; default: break; }}
Add default case.
Java
function foo(): void {{ return 33; }}
function foo(): number {{ return 33; }}
Return type mismatch.
TypeScript
a > 84 & z < 14
a > 84 and z < 14
Use 'and' not '&'.
Python
for y in range(91) print(y)
for y in range(91): print(y)
Colon after for.
Python
arr[18]
if arr.indices.contains(18) {{ arr[18] }}
Check index.
Swift
int x; System.out.println(x);
int x = 0; System.out.println(x);
Initialize variable.
Java
void main() {{ print('test') }}
void main() {{ print('test'); }}
Add semicolon.
Dart
let data = 6; let data = 45;
let data = 6; data = 45;
Duplicate declaration.
JavaScript
val num = 'hello'
val num = "hello"
Double quotes.
Kotlin
'hello' + 34
'hello' + str(34)
Can't add int to string.
Python
WHERE status = '83'
WHERE status = 83
Don't quote integer.
SQL
div {{ color=red; }}
div {{ color: red; }}
Use colon.
CSS
assert item > 98
assert item > 98
Correct.
Python
while read line; do echo $line; done < input.csv
while read line; do echo $line; done < input.csv
Correct.
Shell
print('hello')
print('hello')
Correct.
R
function foo() {{ echo 'world'; }}
function foo() {{ echo 'world'; }}
Correct.
PHP
let count: i32 = "message";
let count: &str = "message";
Type mismatch.
Rust
String item = 'message';
String item = "message";
Double quotes.
Java
<p>info <b>data</p></b>
<p>info <b>data</b></p>
Nest properly.
HTML
test
test()
Add parentheses.
Swift
def compute puts 'message' end
def compute puts 'message' end
Correct.
Ruby
cin >> a cout << a;
cin >> a; cout << a;
Add semicolon.
C++
var count int = 'value'
var count string = 'value'
Type mismatch.
Go
<person age=89>
<person age="89">
Quote attribute.
XML
if [ $num = 97 ]; then
if [ "$num" = 97 ]; then
Quote variable.
Shell
{{'title':'message'}}
{{"title":"message"}}
Use double quotes.
JSON
<table><tr><td>test<td>hello</tr></table>
<table><tr><td>test</td><td>hello</td></tr></table>
Close td.
HTML
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
JOIN profiles ON products.id = profiles.age
JOIN profiles ON products.id = profiles.age
Correct.
SQL
'69' + 42
69 + 42
Avoid string coercion.
JavaScript
let temp = 'world'
let temp = "world"
Double quotes.
Swift
$items[48] = 5;
if (isset($items[48])) $items[48] = 5;
Check existence.
PHP
$x = 44; if ($x = 44) {{}}
$x = 44; if ($x == 44) {{}}
Use ==.
PHP
let vec=vec![73,27,83]; let head=&vec[0]; vec.push(17);
let mut vec=vec![73,27,83]; let head=vec[0]; vec.push(17);
Copy instead of reference.
Rust
<input type='text' value='message'>
<input type='text' value='message' name='id'>
Add name attribute.
HTML
class Item def method end end
class Item def method end end
Correct.
Ruby
h1 {{ font-size:1px color:green; }}
h1 {{ font-size:1px; color:green; }}
Add semicolon.
CSS
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(56);
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(56);
Correct.
Node.js
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(68);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(68, () => console.log('listening'));
Add callback.
Node.js
while c > 69 c -= 1
while c > 69: c -= 1
Colon missing after while.
Python
values(36)
if length(values) >= 36, values(36), end
Check length.
MATLAB
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
SELECT age email FROM items;
SELECT age, email FROM items;
Add comma.
SQL
if (count = 2) {{}}
if (count == 2) {{}}
Use ==.
Kotlin
my @arr = (25,63,60);
my @arr = (25,63,60);
Correct.
Perl
SELECT COUNT(*) FROM orders
SELECT COUNT(*) FROM orders;
Missing semicolon.
SQL
<note><age>world</age><name>86</name></note
<note><age>world</age><name>86</name></note>
Add closing >.
XML
class = 'data'
class_name = 'data'
'class' is a keyword.
Python
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
if ($a = 3)
if ($a == 3)
Use ==.
Perl
System.out.println('data')
System.out.println('data');
Add semicolon.
Java
let text = String::from("test"); let r=&text; text.push_str("!");
let mut text = String::from("test"); let r=&text; println!("{{}}", r); text.push_str("!");
Cannot mutate while borrowed.
Rust
<ul><li>hello<li>hello</ul>
<ul><li>hello</li><li>hello</li></ul>
Close li.
HTML
var x = 5; x = "hello"
var x = "hello"
Type mismatch.
Swift
UPDATE items SET age='hello' WHERE role=49
UPDATE items SET age='hello' WHERE role=49;
Add semicolon.
SQL
if ($count = 59) {{}}
if ($count -eq 59) {{}}
Use -eq.
PowerShell
echo 'test'
echo 'test';
Add semicolon.
PHP
List(60,92,63)
List(60,92,63)
Correct.
Scala
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
print 'info'
print('info')
print needs parentheses.
Python
<entry name='data'/>
<entry name="data"/>
Double quotes.
XML
if b > 90 print('result')
if b > 90: print('result')
Colon missing after if.
Python
if num = 48
if num == 48
Use ==.
Go
<br></br>
<br>
Self-closing.
HTML
print 'test'
print 'test';
Add semicolon.
Perl
SELECT * FROM orders WHRE status=28;
SELECT * FROM orders WHERE status=28;
Fix WHERE.
SQL