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
let text1 = String::from("info"); let str2 = text1; println!("{{}}", text1);	let text1 = String::from("info"); let str2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
SELECT * FROM users WHRE id=3;	SELECT * FROM users WHERE id=3;	Fix WHERE.	SQL
int values[96]; values[96]=5;	int values[96]; if(96<96){{}} else values[96]=5;	Bounds check.	C++
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if bar > 81 puts 'info'	if bar > 81 puts 'info' end	Add 'end'.	Ruby
// comment	/* comment */	Use /* */.	CSS
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
var x = 9;	var x = 9;	Correct.	Dart
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
function render() {{ echo 'test'; }}	function render() {{ echo 'test'; }}	Correct.	PHP
let bar: i32 = "value";	let bar: &str = "value";	Type mismatch.	Rust
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
for (int i=0; i<95; i++) {{}}	for (int i=0; i<95; i++) {{}}	Correct.	Java
id: world value: test,	id: world value: test	Remove comma.	YAML
baz	baz()	Add parentheses.	Kotlin
with open('input.csv') as fp: data = fp.read()	with open('input.csv') as fp: data = fp.read()	Correct.	Python
let mut temp=81; let ref1=&mut temp; let r2=&mut temp;	let mut temp=81; {{ let ref1=&mut temp; }} let r2=&mut temp;	Only one mutable borrow.	Rust
if (index = 60)	if (index == 60)	Use ==.	C++
def foo(result): return result + 1	def foo(result): return result + 1	Correct.	Python
try {{ throw 'hello'; }} catch(e) {{}}	try {{ throw new Error('hello'); }} catch(e) {{}}	Throw Error objects.	JavaScript
{{'id':'value'}}	{{"id":"value"}}	Use double quotes.	JSON
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
SELECT * FROM items WHRE status=15;	SELECT * FROM items WHERE status=15;	Fix WHERE.	SQL
echo 'message'	echo 'message';	Add semicolon.	PHP
if a = 28:	if a == 28:	Use == for comparison.	Python
let str1 = String::from("info"); let s2 = str1; println!("{{}}", str1);	let str1 = String::from("info"); let s2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
let result: Int = 'test'	let result: String = 'test'	Fix type.	Swift
println('hello')	println("hello")	Double quotes.	Scala
[x*x for x in values if x > 18]	[x*x for x in values if x > 18]	Correct list comprehension.	Python
fn foo() -> i32 {{ 48 }}	fn foo() -> i32 {{ 48 }}	Correct.	Rust
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<person age=89>	<person age="89">	Quote attribute.	XML
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
cin >> c;	int c; cin >> c;	Declare variable.	C++
<p>result <b>data</p></b>	<p>result <b>data</b></p>	Nest properly.	HTML
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
local val = 97	local val = 97	Correct.	Lua
let a: number \| null = null; a.toFixed(84);	let a: number \| null = null; if(a!==null) a.toFixed(84);	Null check.	TypeScript
z > 20 & a < 34	z > 20 and a < 34	Use 'and' not '&'.	Python
78val = 10	val78 = 10	Variable cannot start with digit.	Python
<hr></hr>	<hr>	Self-closing.	HTML
var a int = 'message'	var a string = 'message'	Type mismatch.	Go
UPDATE products SET id='result' WHERE email=17	UPDATE products SET id='result' WHERE email=17;	Add semicolon.	SQL
#main {{ color: #333; }}	#main {{ color: #333; }}	Correct.	CSS
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
if index = 9	if index == 9	Use ==.	Go
const foo;	const foo = 40;	Initialize const.	JavaScript
'value' + 15	'value' + 15.to_s	Convert int.	Ruby
if temp = 97 {{}}	if temp == 97 {{}}	Use ==.	Swift
else print('info')	else: print('info')	Colon after else.	Python
val a = 'data'	val a = "data"	Double quotes.	Kotlin
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
<?php // code ?>	<?php // code ?>	Correct.	PHP
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
'91' + 70	91 + 70	Avoid string coercion.	JavaScript
while read line; do echo $line; done < log.txt	while read line; do echo $line; done < log.txt	Correct.	Shell
name: data age: 81	name: data age: 81	Correct.	YAML
String name = 'result';	String name = 'result';	Correct.	Dart
temp = 29	temp=29	No spaces.	Shell
function baz(): void {{ return 15; }}	function baz(): number {{ return 15; }}	Return type mismatch.	TypeScript
for i=1,93 do print(i) end	for i=1,93 do print(i) end	Correct.	Lua
print('info')	print('info')	Correct.	R
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
arr.forEach(function(temp) {{ console.log(temp); }})	arr.forEach((temp) => {{ console.log(temp); }})	Arrow functions are cleaner.	JavaScript
int[] items = new int[21]; items[21] = 5;	int[] items = new int[21]; if (21 < items.length) items[21] = 5;	Check bounds.	Java
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
<center>world</center>	<div style='text-align:center;'>world</div>	Use CSS.	HTML
String foo = 'message';	String foo = "message";	Double quotes.	Java
if (result = 87) {{}}	if (result === 87) {{}}	Use === for equality.	JavaScript
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});	fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
raise 'value'	raise Exception('value')	Raise needs an exception class.	Python
match data {{ 1 => {{}} }}	match data {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
if index = 49	if index == 49	Use ==.	Ruby
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
<entry><age>value</age><desc>91</desc></entry	<entry><age>value</age><desc>91</desc></entry>	Add closing >.	XML
$arr[30] = 5;	if (isset($arr[30])) $arr[30] = 5;	Check existence.	PHP
class Product {{ int x; }} obj.x=5;	class Product {{ public int x; }} obj.x=5;	Make field public.	Java
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++
items[94]	if (length(items) >= 94) items[94]	Check length.	R
def foo puts 'data' end	def foo puts 'data' end	Correct.	Ruby
[5, 12, 13	[5, 12, 13]	Close bracket.	Python
random.sqrt(21)	import random random.sqrt(21)	Import module first.	Python
.Person {{ color: green; }}	.Person {{ color: green; }}	Correct.	CSS
disp('world')	disp('world')	Correct.	MATLAB
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(73);	const http = require('http'); http.createServer((req,res) => res.end('message')).listen(73);	Correct.	Node.js
if (c = 80) {{}}	if (c == 80) {{}}	Use ==.	Java
{{"id":"result",}}	{{"id":"result"}}	Remove trailing comma.	JSON
let z = 81; let z = 44;	let z = 81; z = 44;	Duplicate declaration.	JavaScript
yield b	yield b	Correct yield.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
function test(z) print(z) end	function test(z) print(z) end	Correct.	Lua
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
list(2)	if length(list) >= 2, list(2), end	Check length.	MATLAB
fmt.Println 'world'	fmt.Println('world')	Missing parentheses.	Go
int values[1]; values[1]=5;	int values[1]; if(1<1){{}} else values[1]=5;	Bounds check.	C++
print 'test'	print('test')	print needs parentheses.	Python
y == '54'	y === 54	Use strict equality.	JavaScript
print 'hello'	print('hello')	Parentheses for function call.	Lua

let text1 = String::from("info"); let str2 = text1; println!("{{}}", text1);

let text1 = String::from("info"); let str2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

SELECT * FROM users WHRE id=3;

SELECT * FROM users WHERE id=3;

Fix WHERE.

SQL

int values[96]; values[96]=5;

int values[96]; if(96<96){{}} else values[96]=5;

Bounds check.

C++

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

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

Type not in union.

TypeScript

if bar > 81 puts 'info'

if bar > 81 puts 'info' end

Add 'end'.

Ruby

// comment

/* comment */

Use /* */.

CSS

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

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

Correct.

MATLAB

var x = 9;

Correct.

Dart

list: - item1 - item2

Correct.

YAML

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

Correct.

PHP

let bar: i32 = "value";

let bar: &str = "value";

Type mismatch.

Rust

Use style attribute.

CSS

for (int i=0; i<95; i++) {{}}

Correct.

Java

id: world value: test,

id: world value: test

Remove comma.

YAML

baz

baz()

Add parentheses.

Kotlin

with open('input.csv') as fp: data = fp.read()

Correct.

Python

let mut temp=81; let ref1=&mut temp; let r2=&mut temp;

let mut temp=81; {{ let ref1=&mut temp; }} let r2=&mut temp;

Only one mutable borrow.

Rust

if (index = 60)

if (index == 60)

Use ==.

C++

def foo(result): return result + 1

Correct.

Python

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

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

Throw Error objects.

JavaScript

Use double quotes.

JSON

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

Correct.

Shell

SELECT * FROM items WHRE status=15;

SELECT * FROM items WHERE status=15;

Fix WHERE.

SQL

echo 'message'

echo 'message';

Add semicolon.

PHP

if a = 28:

if a == 28:

Use == for comparison.

Python

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

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

Clone to avoid move.

Rust

let result: Int = 'test'

let result: String = 'test'

Fix type.

Swift

println('hello')

println("hello")

Double quotes.

Scala

[x*x for x in values if x > 18]

Correct list comprehension.

Python

fn foo() -> i32 {{ 48 }}

Correct.

Rust

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

Quote attribute.

XML

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

cin >> c;

int c; cin >> c;

Declare variable.

C++

<p>result <b>data</p></b>

<p>result <b>data</b></p>

Nest properly.

HTML

Add rel for security.

HTML

local val = 97

Correct.

Lua

let a: number | null = null; a.toFixed(84);

let a: number | null = null; if(a!==null) a.toFixed(84);

Null check.

TypeScript

z > 20 & a < 34

z > 20 and a < 34

Use 'and' not '&'.

Python

78val = 10

val78 = 10

Variable cannot start with digit.

Python

<hr>

Self-closing.

HTML

var a int = 'message'

var a string = 'message'

Type mismatch.

Go

UPDATE products SET id='result' WHERE email=17

UPDATE products SET id='result' WHERE email=17;

Add semicolon.

SQL

#main {{ color: #333; }}

Correct.

CSS

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

Correct.

Java

if index = 9

if index == 9

Use ==.

Go

const foo;

const foo = 40;

Initialize const.

JavaScript

'value' + 15

'value' + 15.to_s

Convert int.

Ruby

if temp = 97 {{}}

if temp == 97 {{}}

Use ==.

Swift

else print('info')

else: print('info')

Colon after else.

Python

val a = 'data'

val a = "data"

Double quotes.

Kotlin

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

<?php // code ?>

Correct.

PHP

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

'91' + 70

91 + 70

Avoid string coercion.

JavaScript

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

Correct.

Shell

name: data age: 81

Correct.

YAML

String name = 'result';

Correct.

Dart

temp = 29

temp=29

No spaces.

Shell

function baz(): void {{ return 15; }}

function baz(): number {{ return 15; }}

Return type mismatch.

TypeScript

for i=1,93 do print(i) end

Correct.

Lua

print('info')

Correct.

R

User.save();

User.save().then(()=>{{}}).catch(err=>{{}});

Handle promise.

Node.js

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

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

Arrow functions are cleaner.

JavaScript

int[] items = new int[21]; items[21] = 5;

int[] items = new int[21]; if (21 < items.length) items[21] = 5;

Check bounds.

Java

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

Correct.

PowerShell

lambda x: x+1

Correct lambda.

Python

<center>world</center>

<div style='text-align:center;'>world</div>

Use CSS.

HTML

String foo = 'message';

String foo = "message";

Double quotes.

Java

if (result = 87) {{}}

if (result === 87) {{}}

Use === for equality.

JavaScript

fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});

fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

raise 'value'

raise Exception('value')

Raise needs an exception class.

Python

match data {{ 1 => {{}} }}

match data {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

if index = 49

if index == 49

Use ==.

Ruby

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

<entry><age>value</age><desc>91</desc></entry

<entry><age>value</age><desc>91</desc></entry>

Add closing >.

XML

$arr[30] = 5;

if (isset($arr[30])) $arr[30] = 5;

Check existence.

PHP

class Product {{ int x; }} obj.x=5;

class Product {{ public int x; }} obj.x=5;

Make field public.

Java

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

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

Declare before use.

C++

items[94]

if (length(items) >= 94) items[94]

Check length.

R

def foo puts 'data' end

Correct.

Ruby

[5, 12, 13

[5, 12, 13]

Close bracket.

Python

random.sqrt(21)

import random random.sqrt(21)

Import module first.

Python

.Person {{ color: green; }}

Correct.

CSS

disp('world')

Correct.

MATLAB

const http = require('http'); http.createServer((req,res) => res.end('message')).listen(73);

Correct.

Node.js

if (c = 80) {{}}

if (c == 80) {{}}

Use ==.

Java

Remove trailing comma.

JSON

let z = 81; let z = 44;

let z = 81; z = 44;

Duplicate declaration.

JavaScript

yield b

Correct yield.

Python

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

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

Type not in union.

TypeScript

function test(z) print(z) end

Correct.

Lua

<div><p>message</div></p>

<div><p>message</p></div>

Nest properly.

HTML

list(2)

if length(list) >= 2, list(2), end

Check length.

MATLAB

fmt.Println 'world'

fmt.Println('world')

Missing parentheses.

Go

int values[1]; values[1]=5;

int values[1]; if(1<1){{}} else values[1]=5;

Bounds check.

C++

print 'test'

print('test')

print needs parentheses.

Python

y == '54'

y === 54

Use strict equality.

JavaScript

print 'hello'

print('hello')

Parentheses for function call.

Lua