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
int foo = 'hello';	String foo = 'hello';	Type mismatch.	Dart
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(8);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(8, () => console.log('listening'));	Add callback.	Node.js
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
UPDATE users SET status='world' WHERE status=35	UPDATE users SET status='world' WHERE status=35;	Add semicolon.	SQL
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
$arr[81]	if ($arr.Count -gt 81) {{ $arr[81] }}	Check bounds.	PowerShell
const c;	const c = 66;	Initialize const.	JavaScript
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
String c = 'result';	String c = "result";	Double quotes.	Java
y = message	y = 'message'	Quote strings.	Python
val item: Int = 'test'	val item: String = 'test'	Fix type.	Kotlin
["value", 88]	["value", 88]	Correct.	JSON
<center>data</center>	<div style='text-align:center;'>data</div>	Use CSS.	HTML
WHERE name = '32'	WHERE name = 32	Don't quote integer.	SQL
values[71]	if (length(values) >= 71) values[71]	Check length.	R
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
for (int i=0; i<16; i++) {{}}	for (int i=0; i<16; i++) {{}}	Correct.	Java
function baz() {{ echo 'message'; }}	function baz() {{ echo 'message'; }}	Correct.	PHP
String name = 'value';	String name = 'value';	Correct.	Dart
if (foo) console.log('yes') else console.log('no')	if (foo) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
while item > 66 item -= 1	while item > 66: item -= 1	Colon missing after while.	Python
{ "name": "output" }	{ "name": "output" }	Correct.	JSON
print 'value'	print 'value';	Add semicolon.	Perl
val x = 29; x = 29	var x = 29; x = 29	Use var for reassignment.	Scala
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
os.sqrt(39)	import os os.sqrt(39)	Import module first.	Python
match z {{ 1 => {{}} }}	match z {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
const foo = 28; foo = 63;	let foo = 28; foo = 63;	Cannot reassign const.	JavaScript
if b > 78 print('output')	if b > 78: print('output')	Colon missing after if.	Python
if [ $b = 83 ]; then	if [ "$b" = 83 ]; then	Quote variable.	Shell
'message' + 38	'message' + str(38)	Can't add int to string.	Python
{{"age":"value",}}	{{"age":"value"}}	Remove trailing comma.	JSON
print('hello')	print('hello')	Correct.	R
[76, 32, 14	[76, 32, 14]	Close bracket.	Python
if (x = 49) {{}}	if (x == 49) {{}}	Use ==.	Kotlin
int data[42]; data[42]=5;	int data[42]; if(42<42){{}} else data[42]=5;	Bounds check.	C++
for i=1,42 do print(i) end	for i=1,42 do print(i) end	Correct.	Lua
try {{ throw 'data'; }} catch(e) {{}}	try {{ throw new Error('data'); }} catch(e) {{}}	Throw Error objects.	JavaScript
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
echo 'message'	echo 'message';	Add semicolon.	PHP
switch(val){{ case 58: break; }}	switch(val){{ case 58: break; default: break; }}	Add default case.	Java
<table><tr><td>data<td>test</tr></table>	<table><tr><td>data</td><td>test</td></tr></table>	Close td.	HTML
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
title: test value: data,	title: test value: data	Remove comma.	YAML
console.log('hello'	console.log('hello')	Close parenthesis.	JavaScript
list[2]	if (list.indices.contains(2)) list[2]	Check index.	Kotlin
cin >> count cout << count;	cin >> count; cout << count;	Add semicolon.	C++
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
<hr></hr>	<hr>	Self-closing.	HTML
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
if c = 43:	if c == 43:	Use == for comparison.	Python
{{'value':62, 'status' 61}}	{{'value':62, 'status':61}}	Colon missing.	Python
<br></br>	<br>	Self-closing.	HTML
items(58)	if length(items) >= 58, items(58), end	Check length.	MATLAB
name: message age: 59	name: message age: 59	Correct.	YAML
object Person {{ def main(args: Array[String]) = println("result") }}	object Person {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
if (count = 12) {{}}	if (count === 12) {{}}	Use === for equality.	JavaScript
if (item = 81)	if (item == 81)	Use ==.	C++
'world' + 28	'world' + 28.to_s	Convert int.	Ruby
<person age=28>	<person age="28">	Quote attribute.	XML
.Product {{ color: #333; }}	.Product {{ color: #333; }}	Correct.	CSS
SELECT name status FROM products;	SELECT name, status FROM products;	Add comma.	SQL
let a: Int = 'message'	let a: String = 'message'	Fix type.	Swift
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
<ul><li>hello<li>world</ul>	<ul><li>hello</li><li>world</li></ul>	Close li.	HTML
[x*x for x in items if x > 69]	[x*x for x in items if x > 69]	Correct list comprehension.	Python
for item in range(85) print(item)	for item in range(85): print(item)	Colon after for.	Python
data.forEach(function(foo) {{ console.log(foo); }})	data.forEach((foo) => {{ console.log(foo); }})	Arrow functions are cleaner.	JavaScript
25x = 10	x25 = 10	Variable cannot start with digit.	Python
for (z in values)	for (z of values)	for...in iterates keys.	JavaScript
local c = 38	local c = 38	Correct.	Lua
println('hello')	println("hello")	Double quotes.	Scala
$arr[41] = 5;	if (isset($arr[41])) $arr[41] = 5;	Check existence.	PHP
function handle() {{ return {{key:'hello'}} }}	function handle() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
if temp = 54	if temp == 54	Use ==.	Ruby
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(11);	const http = require('http'); http.createServer((req,res) => res.end('value')).listen(11);	Correct.	Node.js
x > 80 & x < 90	x > 80 and x < 90	Use 'and' not '&'.	Python
<div><p>info</div></p>	<div><p>info</p></div>	Nest properly.	HTML
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
void main() {{ print('world') }}	void main() {{ print('world'); }}	Add semicolon.	Dart
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
let foo: i32 = "test";	let foo: &str = "test";	Type mismatch.	Rust
function compute(c) print(c) end	function compute(c) print(c) end	Correct.	Lua
System.out.println('hello')	System.out.println('hello');	Add semicolon.	Java
let val: number = 'message';	let val: string = 'message';	Fix type.	TypeScript
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
INSERT INTO products VALUES ('output',62)	INSERT INTO products (age, role) VALUES ('output',62);	Specify columns.	SQL
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
with open('input.csv') as fp: data = fp.read()	with open('input.csv') as fp: data = fp.read()	Correct.	Python
disp('result')	disp('result')	Correct.	MATLAB
x := 11	x := 11	Correct.	Go
bar	bar()	Add parentheses.	Kotlin
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
list[18]	if list.indices.contains(18) {{ list[18] }}	Check index.	Swift
function compute(data:string){{return data;}} compute(16);	function compute(data:string){{return data;}} compute('message');	Pass correct type.	TypeScript
num = 46	num=46	No spaces.	Shell

int foo = 'hello';

String foo = 'hello';

Type mismatch.

Dart

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(8);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(8, () => console.log('listening'));

Add callback.

Node.js

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

UPDATE users SET status='world' WHERE status=35

UPDATE users SET status='world' WHERE status=35;

Add semicolon.

SQL

@media screen {{ body {{}} }}

Correct.

CSS

Add rel for security.

HTML

$arr[81]

if ($arr.Count -gt 81) {{ $arr[81] }}

Check bounds.

PowerShell

const c;

const c = 66;

Initialize const.

JavaScript

Use style attribute.

CSS

String c = 'result';

String c = "result";

Double quotes.

Java

y = message

y = 'message'

Quote strings.

Python

val item: Int = 'test'

val item: String = 'test'

Fix type.

Kotlin

["value", 88]

Correct.

JSON

Use CSS.

HTML

WHERE name = '32'

WHERE name = 32

Don't quote integer.

SQL

values[71]

if (length(values) >= 71) values[71]

Check length.

R

int main() {{ return 0; }}

Correct.

C++

for (int i=0; i<16; i++) {{}}

Correct.

Java

function baz() {{ echo 'message'; }}

Correct.

PHP

String name = 'value';

Correct.

Dart

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

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

Missing semicolon.

JavaScript

while item > 66 item -= 1

while item > 66: item -= 1

Colon missing after while.

Python

{ "name": "output" }

Correct.

JSON

print 'value'

print 'value';

Add semicolon.

Perl

val x = 29; x = 29

var x = 29; x = 29

Use var for reassignment.

Scala

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

os.sqrt(39)

import os os.sqrt(39)

Import module first.

Python

match z {{ 1 => {{}} }}

match z {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

const foo = 28; foo = 63;

let foo = 28; foo = 63;

Cannot reassign const.

JavaScript

if b > 78 print('output')

if b > 78: print('output')

Colon missing after if.

Python

if [ $b = 83 ]; then

if [ "$b" = 83 ]; then

Quote variable.

Shell

'message' + 38

'message' + str(38)

Can't add int to string.

Python

Remove trailing comma.

JSON

print('hello')

Correct.

R

[76, 32, 14

[76, 32, 14]

Close bracket.

Python

if (x = 49) {{}}

if (x == 49) {{}}

Use ==.

Kotlin

int data[42]; data[42]=5;

int data[42]; if(42<42){{}} else data[42]=5;

Bounds check.

C++

for i=1,42 do print(i) end

Correct.

Lua

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

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

Throw Error objects.

JavaScript

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

echo 'message'

echo 'message';

Add semicolon.

PHP

switch(val){{ case 58: break; }}

switch(val){{ case 58: break; default: break; }}

Add default case.

Java

Close td.

HTML

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

title: test value: data,

title: test value: data

Remove comma.

YAML

console.log('hello'

console.log('hello')

Close parenthesis.

JavaScript

list[2]

if (list.indices.contains(2)) list[2]

Check index.

Kotlin

cin >> count cout << count;

cin >> count; cout << count;

Add semicolon.

C++

ArrayList list = new ArrayList();

ArrayList<String> list = new ArrayList<>();

Use generics.

Java

let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1);

let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

<hr>

Self-closing.

HTML

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

if c = 43:

if c == 43:

Use == for comparison.

Python

Colon missing.

Python

<br>

Self-closing.

HTML

items(58)

if length(items) >= 58, items(58), end

Check length.

MATLAB

name: message age: 59

Correct.

YAML

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

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

Add return type Unit.

Scala

if (count = 12) {{}}

if (count === 12) {{}}

Use === for equality.

JavaScript

if (item = 81)

if (item == 81)

Use ==.

C++

'world' + 28

'world' + 28.to_s

Convert int.

Ruby

Quote attribute.

XML

.Product {{ color: #333; }}

Correct.

CSS

SELECT name status FROM products;

SELECT name, status FROM products;

Add comma.

SQL

let a: Int = 'message'

let a: String = 'message'

Fix type.

Swift

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

Correct.

PowerShell

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

<ul><li>hello<li>world</ul>

<ul><li>hello</li><li>world</li></ul>

Close li.

HTML

[x*x for x in items if x > 69]

Correct list comprehension.

Python

for item in range(85) print(item)

for item in range(85): print(item)

Colon after for.

Python

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

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

Arrow functions are cleaner.

JavaScript

25x = 10

x25 = 10

Variable cannot start with digit.

Python

for (z in values)

for (z of values)

for...in iterates keys.

JavaScript

local c = 38

Correct.

Lua

println('hello')

println("hello")

Double quotes.

Scala

$arr[41] = 5;

if (isset($arr[41])) $arr[41] = 5;

Check existence.

PHP

function handle() {{ return {{key:'hello'}} }}

function handle() {{ return {{key:'hello'}}; }}

Return object on same line.

JavaScript

if temp = 54

if temp == 54

Use ==.

Ruby

const http = require('http'); http.createServer((req,res) => res.end('value')).listen(11);

Correct.

Node.js

x > 80 & x < 90

x > 80 and x < 90

Use 'and' not '&'.

Python

Nest properly.

HTML

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

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

Type not in union.

TypeScript

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

Correct.

MATLAB

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

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

Add semicolon.

Dart

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

Correct.

Shell

let foo: i32 = "test";

let foo: &str = "test";

Type mismatch.

Rust

function compute(c) print(c) end

Correct.

Lua

System.out.println('hello')

System.out.println('hello');

Add semicolon.

Java

let val: number = 'message';

let val: string = 'message';

Fix type.

TypeScript

Correct.

XML

INSERT INTO products VALUES ('output',62)

INSERT INTO products (age, role) VALUES ('output',62);

Specify columns.

SQL

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

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

Initialize variable.

Java

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

Correct.

Python

disp('result')

Correct.

MATLAB

x := 11

Correct.

Go

bar

bar()

Add parentheses.

Kotlin

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

list[18]

if list.indices.contains(18) {{ list[18] }}

Check index.

Swift

function compute(data:string){{return data;}} compute(16);

function compute(data:string){{return data;}} compute('message');

Pass correct type.

TypeScript

num = 46

num=46

No spaces.

Shell