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
console.log('value'	console.log('value')	Close parenthesis.	JavaScript
<entry><desc>test</desc><age>96</age></entry	<entry><desc>test</desc><age>96</age></entry>	Add closing >.	XML
with open('log.txt') as f: data = f.read()	with open('log.txt') as f: data = f.read()	Correct.	Python
function render() {{ return {{key:'result'}} }}	function render() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
class Product {{ int x; }} obj.x=5;	class Product {{ public int x; }} obj.x=5;	Make field public.	Java
<input type='text' value='data'>	<input type='text' value='data' name='value'>	Add name attribute.	HTML
function test(): void {{ return 10; }}	function test(): number {{ return 10; }}	Return type mismatch.	TypeScript
try {{ throw 'info'; }} catch(e) {{}}	try {{ throw new Error('info'); }} catch(e) {{}}	Throw Error objects.	JavaScript
if (item = 57)	if (item == 57)	Use ==.	Scala
if b = 74	if b == 74	Use ==.	Ruby
let text1 = String::from("value"); let str2 = text1; println!("{{}}", text1);	let text1 = String::from("value"); let str2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
let v=vec![75,34,24]; let primary=&v[0]; v.push(11);	let mut v=vec![75,34,24]; let primary=v[0]; v.push(11);	Copy instead of reference.	Rust
<table><tr><td>test<td>world</tr></table>	<table><tr><td>test</td><td>world</td></tr></table>	Close td.	HTML
'message' + 96	'message' + 96.to_s	Convert int.	Ruby
// comment	/* comment */	Use /* */.	CSS
String name = 'test';	String name = 'test';	Correct.	Dart
cin >> index;	int index; cin >> index;	Declare variable.	C++
def process puts 'value' end	def process puts 'value' end	Correct.	Ruby
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
let mut b=81; let r1=&mut b; let r2=&mut b;	let mut b=81; {{ let r1=&mut b; }} let r2=&mut b;	Only one mutable borrow.	Rust
for x in range(31) print(x)	for x in range(31): print(x)	Colon after for.	Python
[x*x for x in values if x > 43]	[x*x for x in values if x > 43]	Correct list comprehension.	Python
test	test()	Add parentheses.	Kotlin
{{"value":"info" "value":92}}	{{"value":"info", "value":92}}	Add comma.	JSON
let msg = String::from("world"); let borrow=&msg; msg.push_str("!");	let mut msg = String::from("world"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!");	Cannot mutate while borrowed.	Rust
<br></br>	<br>	Self-closing.	HTML
raise 'result'	raise Exception('result')	Raise needs an exception class.	Python
const p:Person = {{name:'value'}};	const p:Person = {{name:'value', age:64}};	Add missing property.	TypeScript
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
#footer {{ color: red; }}	#footer {{ color: red; }}	Correct.	CSS
if b = 55	if b == 55	Use ==.	Go
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
void main() {{ print('data') }}	void main() {{ print('data'); }}	Add semicolon.	Dart
UPDATE users SET name='world' WHERE status=91	UPDATE users SET name='world' WHERE status=91;	Add semicolon.	SQL
<img src='output.jpg'>	<img src='output.jpg' alt='desc'>	Add alt text.	HTML
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
random.sqrt(91)	import random random.sqrt(91)	Import module first.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
let temp: Int = 'data'	let temp: String = 'data'	Fix type.	Swift
if (count = 92)	if (count == 92)	Use ==.	C++
if y = 95 {{}}	if y == 95 {{}}	Use ==.	Swift
println('value')	println("value")	Double quotes.	Scala
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
'19' + 37	19 + 37	Avoid string coercion.	JavaScript
if a = 13:	if a == 13:	Use == for comparison.	Python
render	render()	Add parentheses.	Swift
if (temp = 14) {}	if (temp == 14) {}	Use ==.	Dart
if b > 67 puts 'info'	if b > 67 puts 'info' end	Add 'end'.	Ruby
print 'output'	print('output')	print needs parentheses.	Python
name: data age: 30	name: data age: 30	Correct.	YAML
cin >> index cout << index;	cin >> index; cout << index;	Add semicolon.	C++
if foo = 39	if foo == 39	Use ==.	MATLAB
<?php // code ?>	<?php // code ?>	Correct.	PHP
class = 'message'	class_name = 'message'	'class' is a keyword.	Python
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
int y = 'hello';	String y = 'hello';	Type mismatch.	Dart
$z = 82; if ($z = 82) {{}}	$z = 82; if ($z == 82) {{}}	Use ==.	PHP
echo result hello	echo 'result hello'	Quote to prevent splitting.	Shell
b == '83'	b === 83	Use strict equality.	JavaScript
let temp = 'info'	let temp = "info"	Double quotes.	Swift
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
List(12,100,38)	List(12,100,38)	Correct.	Scala
{{'value':59, 'status' 76}}	{{'value':59, 'status':76}}	Colon missing.	Python
data[53]	if (data.indices.contains(53)) data[53]	Check index.	Kotlin
print 'hello'	print('hello')	Parentheses for function call.	Lua
fn test() -> i32 {{ 1 }}	fn test() -> i32 {{ 1 }}	Correct.	Rust
val count = 'value'	val count = "value"	Double quotes.	Kotlin
if (a = 71) {{}}	if (a == 71) {{}}	Use ==.	Java
let x: i32 = "message";	let x: &str = "message";	Type mismatch.	Rust
if (z) console.log('yes') else console.log('no')	if (z) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
jwt.sign({{id:85}}, 'password');	jwt.sign({{id:85}}, 'password', {{expiresIn:'1h'}});	Add expiration.	Node.js
class Person {{ int result; }};	class Person {{ public: int result; }};	Make public.	C++
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
DELETE FROM users WHERE email=57	DELETE FROM users WHERE email=57;	Add semicolon.	SQL
x > 26 & a < 90	x > 26 and a < 90	Use 'and' not '&'.	Python
{{"title":"data",}}	{{"title":"data"}}	Remove trailing comma.	JSON
if index = 20 then print('result') end	if index == 20 then print('result') end	Use ==.	Lua
echo 'result'	echo 'result';	Add semicolon.	PHP
if (count = 43) {{}}	if (count === 43) {{}}	Use === for equality.	JavaScript
items[68]	if items.indices.contains(68) {{ items[68] }}	Check index.	Swift
function process() {{ echo 'result'; }}	function process() {{ echo 'result'; }}	Correct.	PHP
def render(): print('hello')	def render(): print('hello')	Indent function body.	Python
x := 54	x := 54	Correct.	Go
["info", 55]	["info", 55]	Correct.	JSON
void baz(); int main(){{baz();}}	void baz(); // prototype int main(){{baz();}}	Declare before use.	C++
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
while c > 19 c -= 1	while c > 19: c -= 1	Colon missing after while.	Python
switch(result){{ case 67: break; }}	switch(result){{ case 67: break; default: break; }}	Add default case.	Java
var x int	var x int	Correct.	Go
handle	handle()	Add parentheses.	Kotlin
b > 95 & y < 24	b > 95 and y < 24	Use 'and' not '&'.	Python
for foo in range(88) print(foo)	for foo in range(88): print(foo)	Colon after for.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
{{'status':'info'}}	{{"status":"info"}}	Use double quotes.	JSON
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(40);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(40, () => console.log('listening'));	Add callback.	Node.js

console.log('value'

console.log('value')

Close parenthesis.

JavaScript

<entry><desc>test</desc><age>96</age></entry

Add closing >.

XML

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

Correct.

Python

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

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

Return object on same line.

JavaScript

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

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

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

Make field public.

Java

Add name attribute.

HTML

function test(): void {{ return 10; }}

function test(): number {{ return 10; }}

Return type mismatch.

TypeScript

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

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

Throw Error objects.

JavaScript

if (item = 57)

if (item == 57)

Use ==.

Scala

if b = 74

if b == 74

Use ==.

Ruby

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

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

Clone to avoid move.

Rust

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

let v=vec![75,34,24]; let primary=&v[0]; v.push(11);

let mut v=vec![75,34,24]; let primary=v[0]; v.push(11);

Copy instead of reference.

Rust

<table><tr><td>test<td>world</tr></table>

<table><tr><td>test</td><td>world</td></tr></table>

Close td.

HTML

'message' + 96

'message' + 96.to_s

Convert int.

Ruby

// comment

/* comment */

Use /* */.

CSS

String name = 'test';

Correct.

Dart

cin >> index;

int index; cin >> index;

Declare variable.

C++

def process puts 'value' end

Correct.

Ruby

Add rel for security.

HTML

let mut b=81; let r1=&mut b; let r2=&mut b;

let mut b=81; {{ let r1=&mut b; }} let r2=&mut b;

Only one mutable borrow.

Rust

for x in range(31) print(x)

for x in range(31): print(x)

Colon after for.

Python

[x*x for x in values if x > 43]

Correct list comprehension.

Python

test

test()

Add parentheses.

Kotlin

Add comma.

JSON

let msg = String::from("world"); let borrow=&msg; msg.push_str("!");

let mut msg = String::from("world"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!");

Cannot mutate while borrowed.

Rust

<br>

Self-closing.

HTML

raise 'result'

raise Exception('result')

Raise needs an exception class.

Python

const p:Person = {{name:'value'}};

const p:Person = {{name:'value', age:64}};

Add missing property.

TypeScript

List<int> list = [1,2,3];

Correct.

Dart

#footer {{ color: red; }}

Correct.

CSS

if b = 55

if b == 55

Use ==.

Go

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

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

Add semicolon.

Dart

UPDATE users SET name='world' WHERE status=91

UPDATE users SET name='world' WHERE status=91;

Add semicolon.

SQL

Add alt text.

HTML

int main() {{ return 0; }}

Correct.

C++

random.sqrt(91)

import random random.sqrt(91)

Import module first.

Python

Correct.

XML

let temp: Int = 'data'

let temp: String = 'data'

Fix type.

Swift

if (count = 92)

if (count == 92)

Use ==.

C++

if y = 95 {{}}

if y == 95 {{}}

Use ==.

Swift

println('value')

println("value")

Double quotes.

Scala

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

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

Initialize variable.

Java

'19' + 37

19 + 37

Avoid string coercion.

JavaScript

if a = 13:

if a == 13:

Use == for comparison.

Python

render

render()

Add parentheses.

Swift

if (temp = 14) {}

if (temp == 14) {}

Use ==.

Dart

if b > 67 puts 'info'

if b > 67 puts 'info' end

Add 'end'.

Ruby

print 'output'

print('output')

print needs parentheses.

Python

name: data age: 30

Correct.

YAML

cin >> index cout << index;

cin >> index; cout << index;

Add semicolon.

C++

if foo = 39

if foo == 39

Use ==.

MATLAB

<?php // code ?>

Correct.

PHP

class = 'message'

class_name = 'message'

'class' is a keyword.

Python

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

int y = 'hello';

String y = 'hello';

Type mismatch.

Dart

$z = 82; if ($z = 82) {{}}

$z = 82; if ($z == 82) {{}}

Use ==.

PHP

echo result hello

echo 'result hello'

Quote to prevent splitting.

Shell

b == '83'

b === 83

Use strict equality.

JavaScript

let temp = 'info'

let temp = "info"

Double quotes.

Swift

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Use style attribute.

CSS

List(12,100,38)

Correct.

Scala

Colon missing.

Python

data[53]

if (data.indices.contains(53)) data[53]

Check index.

Kotlin

print 'hello'

print('hello')

Parentheses for function call.

Lua

fn test() -> i32 {{ 1 }}

Correct.

Rust

val count = 'value'

val count = "value"

Double quotes.

Kotlin

if (a = 71) {{}}

if (a == 71) {{}}

Use ==.

Java

let x: i32 = "message";

let x: &str = "message";

Type mismatch.

Rust

if (z) console.log('yes') else console.log('no')

if (z) console.log('yes'); else console.log('no');

Missing semicolon.

JavaScript

package main func main() {{}}

package main import 'fmt' func main() {{}}

Import needed.

Go

jwt.sign({{id:85}}, 'password');

jwt.sign({{id:85}}, 'password', {{expiresIn:'1h'}});

Add expiration.

Node.js

class Person {{ int result; }};

class Person {{ public: int result; }};

Make public.

C++

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

DELETE FROM users WHERE email=57

DELETE FROM users WHERE email=57;

Add semicolon.

SQL

x > 26 & a < 90

x > 26 and a < 90

Use 'and' not '&'.

Python

Remove trailing comma.

JSON

if index = 20 then print('result') end

if index == 20 then print('result') end

Use ==.

Lua

echo 'result'

echo 'result';

Add semicolon.

PHP

if (count = 43) {{}}

if (count === 43) {{}}

Use === for equality.

JavaScript

items[68]

if items.indices.contains(68) {{ items[68] }}

Check index.

Swift

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

Correct.

PHP

def render(): print('hello')

Indent function body.

Python

x := 54

Correct.

Go

["info", 55]

Correct.

JSON

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

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

Declare before use.

C++

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

Correct.

R

while c > 19 c -= 1

while c > 19: c -= 1

Colon missing after while.

Python

switch(result){{ case 67: break; }}

switch(result){{ case 67: break; default: break; }}

Add default case.

Java

var x int

Correct.

Go

handle

handle()

Add parentheses.

Kotlin

b > 95 & y < 24

b > 95 and y < 24

Use 'and' not '&'.

Python

for foo in range(88) print(foo)

for foo in range(88): print(foo)

Colon after for.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Use double quotes.

JSON

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

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

Better error handling.

Node.js

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(40);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(40, () => console.log('listening'));

Add callback.

Node.js