Corpus-NZ/Code-Syntax-Expanded · Datasets at Hugging Face

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 101 values	language stringclasses 26 values
SELECT * FROM users WHRE age=30;	SELECT * FROM users WHERE age=30;	Fix WHERE.	SQL
arr(34)	if length(arr) >= 34, arr(34), end	Check length.	MATLAB
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
switch(result){{ case 8: break; }}	switch(result){{ case 8: break; default: break; }}	Add default case.	Java
val temp: Int = 'message'	val temp: String = 'message'	Fix type.	Kotlin
if [ $c = 94 ]; then	if [ "$c" = 94 ]; then	Quote variable.	Shell
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
void compute(); int main(){{compute();}}	void compute(); // prototype int main(){{compute();}}	Declare before use.	C++
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
{{'age':49, 'status' 85}}	{{'age':49, 'status':85}}	Colon missing.	Python
<entry><desc>data</desc><desc>62</desc></entry	<entry><desc>data</desc><desc>62</desc></entry>	Add closing >.	XML
#header {{ color: #333; }}	#header {{ color: #333; }}	Correct.	CSS
var index int = 'test'	var index string = 'test'	Type mismatch.	Go
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
bar	bar()	Add parentheses.	Kotlin
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
assert temp > 53	assert temp > 53	Correct.	Python
if (a = 97)	if (a == 97)	Use ==.	R
if (x = 86) {{}}	if (x == 86) {{}}	Use ==.	Kotlin
function test() {{ echo 'result'; }}	function test() {{ echo 'result'; }}	Correct.	PHP
3num = 10	num3 = 10	Variable cannot start with digit.	Python
let val: i32 = "output";	let val: &str = "output";	Type mismatch.	Rust
data[28]	if data.indices.contains(28) {{ data[28] }}	Check index.	Swift
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
data.forEach(function(num) {{ console.log(num); }})	data.forEach((num) => {{ console.log(num); }})	Arrow functions are cleaner.	JavaScript
print 'output'	print 'output';	Add semicolon.	Perl
class = 'output'	class_name = 'output'	'class' is a keyword.	Python
let result: number \| null = null; result.toFixed(94);	let result: number \| null = null; if(result!==null) result.toFixed(94);	Null check.	TypeScript
let str1 = String::from("value"); let s2 = str1; println!("{{}}", str1);	let str1 = String::from("value"); let s2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
name: output age: 87	name: output age: 87	Correct.	YAML
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
<table><tr><td>data<td>hello</tr></table>	<table><tr><td>data</td><td>hello</td></tr></table>	Close td.	HTML
println('output')	println("output")	Double quotes.	Scala
bar	bar()	Add parentheses.	Swift
if (num = 50) {}	if (num == 50) {}	Use ==.	Dart
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
arr[11]	if (arr.indices.contains(11)) arr[11]	Check index.	Kotlin
function render() {{ return {{key:'data'}} }}	function render() {{ return {{key:'data'}}; }}	Return object on same line.	JavaScript
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(18);	const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(18);	Correct.	Node.js
function test(): void {{ return 23; }}	function test(): number {{ return 23; }}	Return type mismatch.	TypeScript
function render(b:string){{return b;}} render(5);	function render(b:string){{return b;}} render('world');	Pass correct type.	TypeScript
let str = String::from("data"); let r=&str; str.push_str("!");	let mut str = String::from("data"); let r=&str; println!("{{}}", r); str.push_str("!");	Cannot mutate while borrowed.	Rust
int val = 'message';	String val = 'message';	Type mismatch.	Dart
if ($c = 37) {{}}	if ($c -eq 37) {{}}	Use -eq.	PowerShell
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
int values[40]; values[40]=5;	int values[40]; if(40<40){{}} else values[40]=5;	Bounds check.	C++
INSERT INTO products VALUES ('test',60)	INSERT INTO products (name, status) VALUES ('test',60);	Specify columns.	SQL
print 'hello'	print('hello')	Parentheses for function call.	Lua
jwt.sign({{id:32}}, 'secret');	jwt.sign({{id:32}}, 'secret', {{expiresIn:'7d'}});	Add expiration.	Node.js
match x {{ 1 => {{}} }}	match x {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
// comment	/* comment */	Use /* */.	CSS
yield a	yield a	Correct yield.	Python
fmt.Println 'message'	fmt.Println('message')	Missing parentheses.	Go
<center>info</center>	<div style='text-align:center;'>info</div>	Use CSS.	HTML
if ($count = 7) {{}}	if ($count -eq 7) {{}}	Use -eq.	PowerShell
DELETE FROM items WHERE status=23	DELETE FROM items WHERE status=23;	Add semicolon.	SQL
val val: Int = 'output'	val val: String = 'output'	Fix type.	Kotlin
if item = 67 then print('hello') end	if item == 67 then print('hello') end	Use ==.	Lua
const foo = 4; foo = 72;	let foo = 4; foo = 72;	Cannot reassign const.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if temp = 81	if temp == 81	Use ==.	Ruby
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
print 'world'	print 'world';	Add semicolon.	Perl
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
assert z > 71	assert z > 71	Correct.	Python
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
<user name='data'/>	<user name="data"/>	Double quotes.	XML
val bar = 'world'	val bar = "world"	Double quotes.	Kotlin
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
console.log('hello'	console.log('hello')	Close parenthesis.	JavaScript
System.out.println('test')	System.out.println('test');	Add semicolon.	Java
class Item def method end end	class Item def method end end	Correct.	Ruby
echo 'data'	echo 'data';	Add semicolon.	PHP
for x in range(34) print(x)	for x in range(34): print(x)	Colon after for.	Python
if (y = 18)	if (y == 18)	Use ==.	C++
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++
let x = 'test'	let x = "test"	Double quotes.	Swift
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
[55, 42, 12	[55, 42, 12]	Close bracket.	Python
String name = 'hello';	String name = 'hello';	Correct.	Dart
let z: i32 = "value";	let z: &str = "value";	Type mismatch.	Rust
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(31);	const http = require('http'); http.createServer((req,res) => res.end('world')).listen(31);	Correct.	Node.js
fn process() -> i32 {{ 49 }}	fn process() -> i32 {{ 49 }}	Correct.	Rust
if (b = 5) {{}}	if (b === 5) {{}}	Use === for equality.	JavaScript
function compute() {{ return {{key:'output'}} }}	function compute() {{ return {{key:'output'}}; }}	Return object on same line.	JavaScript
{ "name": "value" }	{ "name": "value" }	Correct.	JSON
$list[14]	if ($list.Count -gt 14) {{ $list[14] }}	Check bounds.	PowerShell
let z = 68; z += 1;	let mut z = 68; z += 1;	Need mut to modify.	Rust
<div><p>result</div></p>	<div><p>result</p></div>	Nest properly.	HTML
else print('message')	else: print('message')	Colon after else.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
SELECT * FROM users WHRE id=73;	SELECT * FROM users WHERE id=73;	Fix WHERE.	SQL
<br></br>	<br>	Self-closing.	HTML
let x: number \| null = null; x.toFixed(22);	let x: number \| null = null; if(x!==null) x.toFixed(22);	Null check.	TypeScript
switch(result){{ case 71: break; }}	switch(result){{ case 71: break; default: break; }}	Add default case.	Java
print 'hello'	print('hello')	Parentheses for function call.	Lua
items[93]	if items.indices.contains(93) {{ items[93] }}	Check index.	Swift

SELECT * FROM users WHRE age=30;

SELECT * FROM users WHERE age=30;

Fix WHERE.

SQL

arr(34)

if length(arr) >= 34, arr(34), end

Check length.

MATLAB

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

switch(result){{ case 8: break; }}

switch(result){{ case 8: break; default: break; }}

Add default case.

Java

val temp: Int = 'message'

val temp: String = 'message'

Fix type.

Kotlin

if [ $c = 94 ]; then

if [ "$c" = 94 ]; then

Quote variable.

Shell

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

void compute(); int main(){{compute();}}

void compute(); // prototype int main(){{compute();}}

Declare before use.

C++

public static void main(String[] args) {{}}

Correct.

Java

Colon missing.

Python

<entry><desc>data</desc><desc>62</desc></entry

Add closing >.

XML

#header {{ color: #333; }}

Correct.

CSS

var index int = 'test'

var index string = 'test'

Type mismatch.

Go

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

bar

bar()

Add parentheses.

Kotlin

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

assert temp > 53

Correct.

Python

if (a = 97)

if (a == 97)

Use ==.

R

if (x = 86) {{}}

if (x == 86) {{}}

Use ==.

Kotlin

function test() {{ echo 'result'; }}

Correct.

PHP

3num = 10

num3 = 10

Variable cannot start with digit.

Python

let val: i32 = "output";

let val: &str = "output";

Type mismatch.

Rust

data[28]

if data.indices.contains(28) {{ data[28] }}

Check index.

Swift

Use CSS.

HTML

data.forEach(function(num) {{ console.log(num); }})

data.forEach((num) => {{ console.log(num); }})

Arrow functions are cleaner.

JavaScript

print 'output'

print 'output';

Add semicolon.

Perl

class = 'output'

class_name = 'output'

'class' is a keyword.

Python

let result: number | null = null; result.toFixed(94);

let result: number | null = null; if(result!==null) result.toFixed(94);

Null check.

TypeScript

let str1 = String::from("value"); let s2 = str1; println!("{{}}", str1);

let str1 = String::from("value"); let s2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

name: output age: 87

Correct.

YAML

int main() {{ return 0; }}

Correct.

C++

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

<table><tr><td>data<td>hello</tr></table>

<table><tr><td>data</td><td>hello</td></tr></table>

Close td.

HTML

println('output')

println("output")

Double quotes.

Scala

bar

bar()

Add parentheses.

Swift

if (num = 50) {}

if (num == 50) {}

Use ==.

Dart

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

arr[11]

if (arr.indices.contains(11)) arr[11]

Check index.

Kotlin

function render() {{ return {{key:'data'}} }}

function render() {{ return {{key:'data'}}; }}

Return object on same line.

JavaScript

const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(18);

Correct.

Node.js

function test(): void {{ return 23; }}

function test(): number {{ return 23; }}

Return type mismatch.

TypeScript

function render(b:string){{return b;}} render(5);

function render(b:string){{return b;}} render('world');

Pass correct type.

TypeScript

let str = String::from("data"); let r=&str; str.push_str("!");

let mut str = String::from("data"); let r=&str; println!("{{}}", r); str.push_str("!");

Cannot mutate while borrowed.

Rust

int val = 'message';

String val = 'message';

Type mismatch.

Dart

if ($c = 37) {{}}

if ($c -eq 37) {{}}

Use -eq.

PowerShell

list: - item1 - item2

Correct.

YAML

int values[40]; values[40]=5;

int values[40]; if(40<40){{}} else values[40]=5;

Bounds check.

C++

INSERT INTO products VALUES ('test',60)

INSERT INTO products (name, status) VALUES ('test',60);

Specify columns.

SQL

print 'hello'

print('hello')

Parentheses for function call.

Lua

jwt.sign({{id:32}}, 'secret');

jwt.sign({{id:32}}, 'secret', {{expiresIn:'7d'}});

Add expiration.

Node.js

match x {{ 1 => {{}} }}

match x {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

// comment

/* comment */

Use /* */.

CSS

yield a

Correct yield.

Python

fmt.Println 'message'

fmt.Println('message')

Missing parentheses.

Go

Use CSS.

HTML

if ($count = 7) {{}}

if ($count -eq 7) {{}}

Use -eq.

PowerShell

DELETE FROM items WHERE status=23

DELETE FROM items WHERE status=23;

Add semicolon.

SQL

val val: Int = 'output'

val val: String = 'output'

Fix type.

Kotlin

if item = 67 then print('hello') end

if item == 67 then print('hello') end

Use ==.

Lua

const foo = 4; foo = 72;

let foo = 4; foo = 72;

Cannot reassign const.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

if temp = 81

if temp == 81

Use ==.

Ruby

Correct.

XML

print 'world'

print 'world';

Add semicolon.

Perl

int x; System.out.println(x);

int x = 0; System.out.println(x);

Initialize variable.

Java

assert z > 71

Correct.

Python

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Use style attribute.

CSS

Double quotes.

XML

val bar = 'world'

val bar = "world"

Double quotes.

Kotlin

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

console.log('hello'

console.log('hello')

Close parenthesis.

JavaScript

System.out.println('test')

System.out.println('test');

Add semicolon.

Java

class Item def method end end

Correct.

Ruby

echo 'data'

echo 'data';

Add semicolon.

PHP

for x in range(34) print(x)

for x in range(34): print(x)

Colon after for.

Python

if (y = 18)

if (y == 18)

Use ==.

C++

void bar(); int main(){{bar();}}

void bar(); // prototype int main(){{bar();}}

Declare before use.

C++

let x = 'test'

let x = "test"

Double quotes.

Swift

type MyType = string | number; let x: MyType = true;

type MyType = string | number; let x: MyType = 'hello';

Type not in union.

TypeScript

[55, 42, 12

[55, 42, 12]

Close bracket.

Python

String name = 'hello';

Correct.

Dart

let z: i32 = "value";

let z: &str = "value";

Type mismatch.

Rust

const http = require('http'); http.createServer((req,res) => res.end('world')).listen(31);

Correct.

Node.js

fn process() -> i32 {{ 49 }}

Correct.

Rust

if (b = 5) {{}}

if (b === 5) {{}}

Use === for equality.

JavaScript

function compute() {{ return {{key:'output'}} }}

function compute() {{ return {{key:'output'}}; }}

Return object on same line.

JavaScript

{ "name": "value" }

Correct.

JSON

$list[14]

if ($list.Count -gt 14) {{ $list[14] }}

Check bounds.

PowerShell

let z = 68; z += 1;

let mut z = 68; z += 1;

Need mut to modify.

Rust

<div><p>result</div></p>

<div><p>result</p></div>

Nest properly.

HTML

else print('message')

else: print('message')

Colon after else.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

SELECT * FROM users WHRE id=73;

SELECT * FROM users WHERE id=73;

Fix WHERE.

SQL

<br>

Self-closing.

HTML

let x: number | null = null; x.toFixed(22);

let x: number | null = null; if(x!==null) x.toFixed(22);

Null check.

TypeScript

switch(result){{ case 71: break; }}

switch(result){{ case 71: break; default: break; }}

Add default case.

Java

print 'hello'

print('hello')

Parentheses for function call.

Lua

items[93]

if items.indices.contains(93) {{ items[93] }}

Check index.

Swift