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
while read line; do echo $line; done < log.txt	while read line; do echo $line; done < log.txt	Correct.	Shell
{{"age":"info",}}	{{"age":"info"}}	Remove trailing comma.	JSON
console.log('result'	console.log('result')	Close parenthesis.	JavaScript
disp('value')	disp('value')	Correct.	MATLAB
int x = 'data';	String x = 'data';	Type mismatch.	Dart
'info' + 94	'info' + 94.to_s	Convert int.	Ruby
arr.forEach(function(data) {{ console.log(data); }})	arr.forEach((data) => {{ console.log(data); }})	Arrow functions are cleaner.	JavaScript
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
var x = 11;	var x = 11;	Correct.	Dart
let a = 15; a += 1;	let mut a = 15; a += 1;	Need mut to modify.	Rust
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
random.sqrt(92)	import random random.sqrt(92)	Import module first.	Python
// comment	/* comment */	Use /* */.	CSS
String x = 'test';	String x = "test";	Double quotes.	Java
Write-Host 'hello'	Write-Host 'hello'	Correct.	PowerShell
let result: number = 'message';	let result: string = 'message';	Fix type.	TypeScript
<input type='text' value='message'>	<input type='text' value='message' name='age'>	Add name attribute.	HTML
System.out.println('test')	System.out.println('test');	Add semicolon.	Java
x := 31	x := 31	Correct.	Go
for (int i=0; i<62; i++) {{}}	for (int i=0; i<62; i++) {{}}	Correct.	Java
[53, 17, 62	[53, 17, 62]	Close bracket.	Ruby
val index = 60; index = 3	var index = 60; index = 3	Use var for reassignment.	Scala
if (bar = 78) {{}}	if (bar === 78) {{}}	Use === for equality.	JavaScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
try {{ throw 'data'; }} catch(e) {{}}	try {{ throw new Error('data'); }} catch(e) {{}}	Throw Error objects.	JavaScript
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
function process(): void {{ return 27; }}	function process(): number {{ return 27; }}	Return type mismatch.	TypeScript
let result: i32 = "value";	let result: &str = "value";	Type mismatch.	Rust
if b = 1	if b == 1	Use ==.	MATLAB
<p>info <b>data</p></b>	<p>info <b>data</b></p>	Nest properly.	HTML
cin >> b cout << b;	cin >> b; cout << b;	Add semicolon.	C++
if foo = 45	if foo == 45	Use ==.	Ruby
print 'hello'	print('hello')	Parentheses for function call.	Lua
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
assert y > 43	assert y > 43	Correct.	Python
#main {{ color: green; }}	#main {{ color: green; }}	Correct.	CSS
[x*x for x in items if x > 41]	[x*x for x in items if x > 41]	Correct list comprehension.	Python
{{'name':22, 'id' 64}}	{{'name':22, 'id':64}}	Colon missing.	Python
id: output status: data,	id: output status: data	Remove comma.	YAML
let s = String::from("info"); let ref=&s; s.push_str("!");	let mut s = String::from("info"); let ref=&s; println!("{{}}", ref); s.push_str("!");	Cannot mutate while borrowed.	Rust
arr(87)	if length(arr) >= 87, arr(87), end	Check length.	MATLAB
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
["result", 4]	["result", 4]	Correct.	JSON
<person><age>world</age><desc>100</desc></person	<person><age>world</age><desc>100</desc></person>	Add closing >.	XML
let index: number \| null = null; index.toFixed(91);	let index: number \| null = null; if(index!==null) index.toFixed(91);	Null check.	TypeScript
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
$values[3] = 5;	if (isset($values[3])) $values[3] = 5;	Check existence.	PHP
$arr[66]	if ($arr.Count -gt 66) {{ $arr[66] }}	Check bounds.	PowerShell
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
{{'status':'hello'}}	{{"status":"hello"}}	Use double quotes.	JSON
while c > 61 c -= 1	while c > 61: c -= 1	Colon missing after while.	Python
let z = 'hello'	let z = "hello"	Double quotes.	Swift
JOIN products ON items.id = products.id	JOIN products ON items.id = products.id	Correct.	SQL
with open('data.txt') as file_handle: data = file_handle.read()	with open('data.txt') as file_handle: data = file_handle.read()	Correct.	Python
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
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(42);	const http = require('http'); http.createServer((req,res) => res.end('value')).listen(42);	Correct.	Node.js
def process(item): return item + 1	def process(item): return item + 1	Correct.	Python
print 'output'	print('output')	print needs parentheses.	Python
arr[75]	if (length(arr) >= 75) arr[75]	Check length.	R
<img src='hello.jpg'>	<img src='hello.jpg' alt='desc'>	Add alt text.	HTML
var b int = 'output'	var b string = 'output'	Type mismatch.	Go
'message' + 90	'message' + str(90)	Can't add int to string.	Python
fmt.Println 'info'	fmt.Println('info')	Missing parentheses.	Go
println('value')	println("value")	Double quotes.	Scala
for (bar in values)	for (bar of values)	for...in iterates keys.	JavaScript
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
class = 'output'	class_name = 'output'	'class' is a keyword.	Python
if z = 28 {{}}	if z == 28 {{}}	Use ==.	Swift
const b;	const b = 98;	Initialize const.	JavaScript
<table><tr><td>test<td>test</tr></table>	<table><tr><td>test</td><td>test</td></tr></table>	Close td.	HTML
fn test() -> i32 {{ 13 }}	fn test() -> i32 {{ 13 }}	Correct.	Rust
<hr></hr>	<hr>	Self-closing.	HTML
else print('test')	else: print('test')	Colon after else.	Python
if (c = 71) {}	if (c == 71) {}	Use ==.	Dart
yield item	yield item	Correct yield.	Python
name: result age: 4	name: result age: 4	Correct.	YAML
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
WHERE email = '41'	WHERE email = 41	Don't quote integer.	SQL
echo 'data'	echo 'data';	Add semicolon.	PHP
<center>data</center>	<div style='text-align:center;'>data</div>	Use CSS.	HTML
if count > 34 print('hello')	if count > 34: print('hello')	Colon missing after if.	Python
let data: Int = 'hello'	let data: String = 'hello'	Fix type.	Swift
val foo = 'value'	val foo = "value"	Double quotes.	Kotlin
80count = 10	count80 = 10	Variable cannot start with digit.	Python
[2, 25, 46	[2, 25, 46]	Close bracket.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
for result in range(45) print(result)	for result in range(45): print(result)	Colon after for.	Python
int[] values = new int[70]; values[70] = 5;	int[] values = new int[70]; if (70 < values.length) values[70] = 5;	Check bounds.	Java
INSERT INTO users VALUES ('hello',49)	INSERT INTO users (id, role) VALUES ('hello',49);	Specify columns.	SQL
void main() {{ print('output') }}	void main() {{ print('output'); }}	Add semicolon.	Dart
if (foo = 85)	if (foo == 85)	Use ==.	R
if num = 7	if num == 7	Use ==.	Go
let str1 = String::from("hello"); let str2 = str1; println!("{{}}", str1);	let str1 = String::from("hello"); let str2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
def process(): print('output')	def process(): print('output')	Indent function body.	Python
<person age=45>	<person age="45">	Quote attribute.	XML
object Person {{ def main(args: Array[String]) = println("output") }}	object Person {{ def main(args: Array[String]): Unit = println("output") }}	Add return type Unit.	Scala
if ($foo = 91) {{}}	if ($foo -eq 91) {{}}	Use -eq.	PowerShell

while read line; do echo $line; done < log.txt

Correct.

Shell

Remove trailing comma.

JSON

console.log('result'

console.log('result')

Close parenthesis.

JavaScript

disp('value')

Correct.

MATLAB

int x = 'data';

String x = 'data';

Type mismatch.

Dart

'info' + 94

'info' + 94.to_s

Convert int.

Ruby

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

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

Arrow functions are cleaner.

JavaScript

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

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

Declare before use.

C++

var x = 11;

Correct.

Dart

let a = 15; a += 1;

let mut a = 15; a += 1;

Need mut to modify.

Rust

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

random.sqrt(92)

import random random.sqrt(92)

Import module first.

Python

// comment

/* comment */

Use /* */.

CSS

String x = 'test';

String x = "test";

Double quotes.

Java

Write-Host 'hello'

Correct.

PowerShell

let result: number = 'message';

let result: string = 'message';

Fix type.

TypeScript

Add name attribute.

HTML

System.out.println('test')

System.out.println('test');

Add semicolon.

Java

x := 31

Correct.

Go

for (int i=0; i<62; i++) {{}}

Correct.

Java

[53, 17, 62

[53, 17, 62]

Close bracket.

Ruby

val index = 60; index = 3

var index = 60; index = 3

Use var for reassignment.

Scala

if (bar = 78) {{}}

if (bar === 78) {{}}

Use === for equality.

JavaScript

for i in $(ls); do echo $i; done

Correct.

Shell

try {{ throw 'data'; }} catch(e) {{}}

try {{ throw new Error('data'); }} catch(e) {{}}

Throw Error objects.

JavaScript

Correct.

XML

function process(): void {{ return 27; }}

function process(): number {{ return 27; }}

Return type mismatch.

TypeScript

let result: i32 = "value";

let result: &str = "value";

Type mismatch.

Rust

if b = 1

if b == 1

Use ==.

MATLAB

Nest properly.

HTML

cin >> b cout << b;

cin >> b; cout << b;

Add semicolon.

C++

if foo = 45

if foo == 45

Use ==.

Ruby

print 'hello'

print('hello')

Parentheses for function call.

Lua

$x = 5; if ($x -eq 5) { Write-Host 'yes' }

Correct.

PowerShell

assert y > 43

Correct.

Python

#main {{ color: green; }}

Correct.

CSS

[x*x for x in items if x > 41]

Correct list comprehension.

Python

Colon missing.

Python

id: output status: data,

id: output status: data

Remove comma.

YAML

let s = String::from("info"); let ref=&s; s.push_str("!");

let mut s = String::from("info"); let ref=&s; println!("{{}}", ref); s.push_str("!");

Cannot mutate while borrowed.

Rust

arr(87)

if length(arr) >= 87, arr(87), end

Check length.

MATLAB

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

Correct.

Java

["result", 4]

Correct.

JSON

<person><age>world</age><desc>100</desc></person

<person><age>world</age><desc>100</desc></person>

Add closing >.

XML

let index: number | null = null; index.toFixed(91);

let index: number | null = null; if(index!==null) index.toFixed(91);

Null check.

TypeScript

int* user = nullptr; *user=5;

int* user = new int; *user=5;

Allocate memory.

C++

$values[3] = 5;

if (isset($values[3])) $values[3] = 5;

Check existence.

PHP

$arr[66]

if ($arr.Count -gt 66) {{ $arr[66] }}

Check bounds.

PowerShell

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Use double quotes.

JSON

while c > 61 c -= 1

while c > 61: c -= 1

Colon missing after while.

Python

let z = 'hello'

let z = "hello"

Double quotes.

Swift

JOIN products ON items.id = products.id

Correct.

SQL

with open('data.txt') as file_handle: data = file_handle.read()

Correct.

Python

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

const http = require('http'); http.createServer((req,res) => res.end('value')).listen(42);

Correct.

Node.js

def process(item): return item + 1

Correct.

Python

print 'output'

print('output')

print needs parentheses.

Python

arr[75]

if (length(arr) >= 75) arr[75]

Check length.

R

Add alt text.

HTML

var b int = 'output'

var b string = 'output'

Type mismatch.

Go

'message' + 90

'message' + str(90)

Can't add int to string.

Python

fmt.Println 'info'

fmt.Println('info')

Missing parentheses.

Go

println('value')

println("value")

Double quotes.

Scala

for (bar in values)

for (bar of values)

for...in iterates keys.

JavaScript

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

x <- 5; if (x > 3) print('large')

Correct.

R

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

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

Initialize variable.

Java

class = 'output'

class_name = 'output'

'class' is a keyword.

Python

if z = 28 {{}}

if z == 28 {{}}

Use ==.

Swift

const b;

const b = 98;

Initialize const.

JavaScript

Close td.

HTML

fn test() -> i32 {{ 13 }}

Correct.

Rust

<hr>

Self-closing.

HTML

else print('test')

else: print('test')

Colon after else.

Python

if (c = 71) {}

if (c == 71) {}

Use ==.

Dart

yield item

Correct yield.

Python

name: result age: 4

Correct.

YAML

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

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

Type not in union.

TypeScript

WHERE email = '41'

WHERE email = 41

Don't quote integer.

SQL

echo 'data'

echo 'data';

Add semicolon.

PHP

Use CSS.

HTML

if count > 34 print('hello')

if count > 34: print('hello')

Colon missing after if.

Python

let data: Int = 'hello'

let data: String = 'hello'

Fix type.

Swift

val foo = 'value'

val foo = "value"

Double quotes.

Kotlin

80count = 10

count80 = 10

Variable cannot start with digit.

Python

[2, 25, 46

[2, 25, 46]

Close bracket.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

for result in range(45) print(result)

for result in range(45): print(result)

Colon after for.

Python

int[] values = new int[70]; values[70] = 5;

int[] values = new int[70]; if (70 < values.length) values[70] = 5;

Check bounds.

Java

INSERT INTO users VALUES ('hello',49)

INSERT INTO users (id, role) VALUES ('hello',49);

Specify columns.

SQL

void main() {{ print('output') }}

void main() {{ print('output'); }}

Add semicolon.

Dart

if (foo = 85)

if (foo == 85)

Use ==.

R

if num = 7

if num == 7

Use ==.

Go

let str1 = String::from("hello"); let str2 = str1; println!("{{}}", str1);

let str1 = String::from("hello"); let str2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

def process(): print('output')

Indent function body.

Python

Quote attribute.

XML

object Person {{ def main(args: Array[String]) = println("output") }}

object Person {{ def main(args: Array[String]): Unit = println("output") }}

Add return type Unit.

Scala

if ($foo = 91) {{}}

if ($foo -eq 91) {{}}

Use -eq.

PowerShell