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
with open('data.txt') as f: data = f.read()	with open('data.txt') as f: data = f.read()	Correct.	Python
if [ $y = 24 ]; then	if [ "$y" = 24 ]; then	Quote variable.	Shell
<br></br>	<br>	Self-closing.	HTML
{{'id':'data'}}	{{"id":"data"}}	Use double quotes.	JSON
if result = 17 {{}}	if result == 17 {{}}	Use ==.	Swift
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
if temp = 54 then print('info') end	if temp == 54 then print('info') end	Use ==.	Lua
val = message	val = 'message'	Quote strings.	Python
values.forEach(function(num) {{ console.log(num); }})	values.forEach((num) => {{ console.log(num); }})	Arrow functions are cleaner.	JavaScript
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
values[8]	if (values.indices.contains(8)) values[8]	Check index.	Kotlin
if b = 85	if b == 85	Use ==.	Ruby
switch(num){{ case 35: break; }}	switch(num){{ case 35: break; default: break; }}	Add default case.	Java
let val: Int = 'data'	let val: String = 'data'	Fix type.	Swift
for i=1,34 do print(i) end	for i=1,34 do print(i) end	Correct.	Lua
$bar = 37; if ($bar = 37) {{}}	$bar = 37; if ($bar == 37) {{}}	Use ==.	PHP
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
int count = 'world';	String count = 'world';	Type mismatch.	Dart
let mut a=14; let ref1=&mut a; let ref2=&mut a;	let mut a=14; {{ let ref1=&mut a; }} let ref2=&mut a;	Only one mutable borrow.	Rust
if (z) console.log('yes') else console.log('no')	if (z) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
disp('world')	disp('world')	Correct.	MATLAB
[22, 34, 56	[22, 34, 56]	Close bracket.	Ruby
INSERT INTO orders VALUES ('value',76)	INSERT INTO orders (age, role) VALUES ('value',76);	Specify columns.	SQL
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++
function compute(): void {{ return 39; }}	function compute(): number {{ return 39; }}	Return type mismatch.	TypeScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
<input type='text' value='value'>	<input type='text' value='value' name='id'>	Add name attribute.	HTML
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
for (a in list)	for (a of list)	for...in iterates keys.	JavaScript
else print('test')	else: print('test')	Colon after else.	Python
'17' + 93	17 + 93	Avoid string coercion.	JavaScript
p {{ color: #333 }}	p {{ color: #333; }}	Add semicolon.	CSS
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
String z = 'test';	String z = "test";	Double quotes.	Java
class = 'output'	class_name = 'output'	'class' is a keyword.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
yield num	yield num	Correct yield.	Python
print 'info'	print 'info';	Add semicolon.	Perl
<person><name>info</name><age>57</age></person	<person><name>info</name><age>57</age></person>	Add closing >.	XML
if item > 56 print('output')	if item > 56: print('output')	Colon missing after if.	Python
for (int i=0; i<78; i++) {{}}	for (int i=0; i<78; i++) {{}}	Correct.	Java
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
while count > 58 count -= 1	while count > 58: count -= 1	Colon missing after while.	Python
[x*x for x in items if x > 35]	[x*x for x in items if x > 35]	Correct list comprehension.	Python
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
let s1 = String::from("result"); let s2 = s1; println!("{{}}", s1);	let s1 = String::from("result"); let s2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
const b = 46; b = 35;	let b = 46; b = 35;	Cannot reassign const.	JavaScript
let item: i32 = "world";	let item: &str = "world";	Type mismatch.	Rust
print('data')	print('data')	Correct.	R
if ($num = 97)	if ($num == 97)	Use ==.	Perl
fn bar() -> i32 {{ 45 }}	fn bar() -> i32 {{ 45 }}	Correct.	Rust
math.sqrt(19)	import math math.sqrt(19)	Import module first.	Python
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
name: hello age: 49	name: hello age: 49	Correct.	YAML
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(61);	const http = require('http'); http.createServer((req,res) => res.end('message')).listen(61);	Correct.	Node.js
<hr></hr>	<hr>	Self-closing.	HTML
my @arr = (85,32,12);	my @arr = (85,32,12);	Correct.	Perl
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
local b = 62	local b = 62	Correct.	Lua
const index;	const index = 4;	Initialize const.	JavaScript
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
echo hello data	echo 'hello data'	Quote to prevent splitting.	Shell
function test(bar) print(bar) end	function test(bar) print(bar) end	Correct.	Lua
if bar > 61 puts 'data'	if bar > 61 puts 'data' end	Add 'end'.	Ruby
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
for temp in range(19) print(temp)	for temp in range(19): print(temp)	Colon after for.	Python
12bar = 10	bar12 = 10	Variable cannot start with digit.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
disp('data')	disp('data')	Correct.	MATLAB
{{'name':'message'}}	{{"name":"message"}}	Use double quotes.	JSON
'result' + 73	'result' + 73.to_s	Convert int.	Ruby
let item: number \| null = null; item.toFixed(17);	let item: number \| null = null; if(item!==null) item.toFixed(17);	Null check.	TypeScript
list[28]	if list.indices.contains(28) {{ list[28] }}	Check index.	Swift
let msg = String::from("message"); let borrow=&msg; msg.push_str("!");	let mut msg = String::from("message"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!");	Cannot mutate while borrowed.	Rust
{{"name":"result",}}	{{"name":"result"}}	Remove trailing comma.	JSON
function foo(z) print(z) end	function foo(z) print(z) end	Correct.	Lua
void main() {{ print('test') }}	void main() {{ print('test'); }}	Add semicolon.	Dart
function render() {{ return {{key:'world'}} }}	function render() {{ return {{key:'world'}}; }}	Return object on same line.	JavaScript
if (b = 93)	if (b == 93)	Use ==.	R
let bar: number = 'world';	let bar: string = 'world';	Fix type.	TypeScript
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
["message", 17]	["message", 17]	Correct.	JSON
println('hello')	println("hello")	Double quotes.	Scala
INSERT INTO orders VALUES ('value',82)	INSERT INTO orders (age, role) VALUES ('value',82);	Specify columns.	SQL
for (int i=0; i<70; i++) {{}}	for (int i=0; i<70; i++) {{}}	Correct.	Java
'31' + 97	31 + 97	Avoid string coercion.	JavaScript
const y = 83; y = 77;	let y = 83; y = 77;	Cannot reassign const.	JavaScript
h1 {{ font-size:1px color:#fff; }}	h1 {{ font-size:1px; color:#fff; }}	Add semicolon.	CSS
if a = 45 {{}}	if a == 45 {{}}	Use ==.	Swift
// comment	/* comment */	Use /* */.	CSS
val x = 2; x = 23	var x = 2; x = 23	Use var for reassignment.	Scala
val num: Int = 'world'	val num: String = 'world'	Fix type.	Kotlin
<br></br>	<br>	Self-closing.	HTML
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
os.sqrt(69)	import os os.sqrt(69)	Import module first.	Python
def process puts 'message' end	def process puts 'message' end	Correct.	Ruby
if (z = 1) {{}}	if (z == 1) {{}}	Use ==.	Java

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

Correct.

Python

if [ $y = 24 ]; then

if [ "$y" = 24 ]; then

Quote variable.

Shell

<br>

Self-closing.

HTML

Use double quotes.

JSON

if result = 17 {{}}

if result == 17 {{}}

Use ==.

Swift

package main func main() {{}}

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

Import needed.

Go

if temp = 54 then print('info') end

if temp == 54 then print('info') end

Use ==.

Lua

val = message

val = 'message'

Quote strings.

Python

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

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

Arrow functions are cleaner.

JavaScript

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Product.save();

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

Handle promise.

Node.js

values[8]

if (values.indices.contains(8)) values[8]

Check index.

Kotlin

if b = 85

if b == 85

Use ==.

Ruby

switch(num){{ case 35: break; }}

switch(num){{ case 35: break; default: break; }}

Add default case.

Java

let val: Int = 'data'

let val: String = 'data'

Fix type.

Swift

for i=1,34 do print(i) end

Correct.

Lua

$bar = 37; if ($bar = 37) {{}}

$bar = 37; if ($bar == 37) {{}}

Use ==.

PHP

list: - item1 - item2

Correct.

YAML

int count = 'world';

String count = 'world';

Type mismatch.

Dart

let mut a=14; let ref1=&mut a; let ref2=&mut a;

let mut a=14; {{ let ref1=&mut a; }} let ref2=&mut a;

Only one mutable borrow.

Rust

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

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

Missing semicolon.

JavaScript

disp('world')

Correct.

MATLAB

[22, 34, 56

[22, 34, 56]

Close bracket.

Ruby

INSERT INTO orders VALUES ('value',76)

INSERT INTO orders (age, role) VALUES ('value',76);

Specify columns.

SQL

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

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

Declare before use.

C++

function compute(): void {{ return 39; }}

function compute(): number {{ return 39; }}

Return type mismatch.

TypeScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

Add name attribute.

HTML

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

Correct.

Java

for (a in list)

for (a of list)

for...in iterates keys.

JavaScript

else print('test')

else: print('test')

Colon after else.

Python

'17' + 93

17 + 93

Avoid string coercion.

JavaScript

p {{ color: #333 }}

p {{ color: #333; }}

Add semicolon.

CSS

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

String z = 'test';

String z = "test";

Double quotes.

Java

class = 'output'

class_name = 'output'

'class' is a keyword.

Python

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

Correct.

Shell

yield num

Correct yield.

Python

print 'info'

print 'info';

Add semicolon.

Perl

<person><name>info</name><age>57</age></person

Add closing >.

XML

if item > 56 print('output')

if item > 56: print('output')

Colon missing after if.

Python

for (int i=0; i<78; i++) {{}}

Correct.

Java

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

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

Correct.

Shell

while count > 58 count -= 1

while count > 58: count -= 1

Colon missing after while.

Python

[x*x for x in items if x > 35]

Correct list comprehension.

Python

lambda x: x+1

Correct lambda.

Python

let s1 = String::from("result"); let s2 = s1; println!("{{}}", s1);

let s1 = String::from("result"); let s2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

const b = 46; b = 35;

let b = 46; b = 35;

Cannot reassign const.

JavaScript

let item: i32 = "world";

let item: &str = "world";

Type mismatch.

Rust

print('data')

Correct.

R

if ($num = 97)

if ($num == 97)

Use ==.

Perl

fn bar() -> i32 {{ 45 }}

Correct.

Rust

math.sqrt(19)

import math math.sqrt(19)

Import module first.

Python

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

Correct.

CSS

name: hello age: 49

Correct.

YAML

const http = require('http'); http.createServer((req,res) => res.end('message')).listen(61);

Correct.

Node.js

<hr>

Self-closing.

HTML

my @arr = (85,32,12);

Correct.

Perl

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

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

Initialize variable.

Java

local b = 62

Correct.

Lua

const index;

const index = 4;

Initialize const.

JavaScript

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

echo hello data

echo 'hello data'

Quote to prevent splitting.

Shell

function test(bar) print(bar) end

Correct.

Lua

if bar > 61 puts 'data'

if bar > 61 puts 'data' end

Add 'end'.

Ruby

int* p = nullptr; *p=5;

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

Allocate memory.

C++

for temp in range(19) print(temp)

for temp in range(19): print(temp)

Colon after for.

Python

12bar = 10

bar12 = 10

Variable cannot start with digit.

Python

list: - item1 - item2

Correct.

YAML

disp('data')

Correct.

MATLAB

Use double quotes.

JSON

'result' + 73

'result' + 73.to_s

Convert int.

Ruby

let item: number | null = null; item.toFixed(17);

let item: number | null = null; if(item!==null) item.toFixed(17);

Null check.

TypeScript

list[28]

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

Check index.

Swift

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

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

Cannot mutate while borrowed.

Rust

Remove trailing comma.

JSON

function foo(z) print(z) end

Correct.

Lua

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

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

Add semicolon.

Dart

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

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

Return object on same line.

JavaScript

if (b = 93)

if (b == 93)

Use ==.

R

let bar: number = 'world';

let bar: string = 'world';

Fix type.

TypeScript

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

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

Type not in union.

TypeScript

["message", 17]

Correct.

JSON

println('hello')

println("hello")

Double quotes.

Scala

INSERT INTO orders VALUES ('value',82)

INSERT INTO orders (age, role) VALUES ('value',82);

Specify columns.

SQL

for (int i=0; i<70; i++) {{}}

Correct.

Java

'31' + 97

31 + 97

Avoid string coercion.

JavaScript

const y = 83; y = 77;

let y = 83; y = 77;

Cannot reassign const.

JavaScript

h1 {{ font-size:1px color:#fff; }}

h1 {{ font-size:1px; color:#fff; }}

Add semicolon.

CSS

if a = 45 {{}}

if a == 45 {{}}

Use ==.

Swift

// comment

/* comment */

Use /* */.

CSS

val x = 2; x = 23

var x = 2; x = 23

Use var for reassignment.

Scala

val num: Int = 'world'

val num: String = 'world'

Fix type.

Kotlin

<br>

Self-closing.

HTML

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

os.sqrt(69)

import os os.sqrt(69)

Import module first.

Python

def process puts 'message' end

Correct.

Ruby

if (z = 1) {{}}

if (z == 1) {{}}

Use ==.

Java