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
if num > 5 print('message')	if num > 5: print('message')	Colon missing after if.	Python
void main() {{ print('world') }}	void main() {{ print('world'); }}	Add semicolon.	Dart
Write-Host 'result'	Write-Host 'result'	Correct.	PowerShell
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
val foo: Int = 'output'	val foo: String = 'output'	Fix type.	Kotlin
object Product {{ def main(args: Array[String]) = println("message") }}	object Product {{ def main(args: Array[String]): Unit = println("message") }}	Add return type Unit.	Scala
if c = 99 then print('value') end	if c == 99 then print('value') end	Use ==.	Lua
if (count = 100) {{}}	if (count == 100) {{}}	Use ==.	Java
if (a = 44) {{}}	if (a == 44) {{}}	Use ==.	Kotlin
data(25)	if length(data) >= 25, data(25), end	Check length.	MATLAB
data[12]	if (length(data) >= 12) data[12]	Check length.	R
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
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
if (c = 47)	if (c == 47)	Use ==.	R
if [ $x = 93 ]; then	if [ "$x" = 93 ]; then	Quote variable.	Shell
let z = 51; z += 1;	let mut z = 51; z += 1;	Need mut to modify.	Rust
if index = 79	if index == 79	Use ==.	MATLAB
try {{ throw 'message'; }} catch(e) {{}}	try {{ throw new Error('message'); }} catch(e) {{}}	Throw Error objects.	JavaScript
SELECT * FROM users WHRE age=64;	SELECT * FROM users WHERE age=64;	Fix WHERE.	SQL
let result = 'value'	let result = "value"	Double quotes.	Swift
var data int = 'result'	var data string = 'result'	Type mismatch.	Go
h1 {{ font-size:5px color:blue; }}	h1 {{ font-size:5px; color:blue; }}	Add semicolon.	CSS
if c = 77:	if c == 77:	Use == for comparison.	Python
div {{ color=#fff; }}	div {{ color: #fff; }}	Use colon.	CSS
<table><tr><td>test<td>hello</tr></table>	<table><tr><td>test</td><td>hello</td></tr></table>	Close td.	HTML
'info' + 16	'info' + 16.to_s	Convert int.	Ruby
if (c) console.log('yes') else console.log('no')	if (c) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
if (result = 54) {}	if (result == 54) {}	Use ==.	Dart
'test' + 20	'test' + str(20)	Can't add int to string.	Python
["result", 59]	["result", 59]	Correct.	JSON
function handle(item:string){{return item;}} handle(11);	function handle(item:string){{return item;}} handle('info');	Pass correct type.	TypeScript
$index = 23; if ($index = 23) {{}}	$index = 23; if ($index == 23) {{}}	Use ==.	PHP
let data: number = 'hello';	let data: string = 'hello';	Fix type.	TypeScript
if ($b = 80)	if ($b == 80)	Use ==.	Perl
class Product def method end end	class Product def method end end	Correct.	Ruby
let data: i32 = "data";	let data: &str = "data";	Type mismatch.	Rust
int x = 'hello';	String x = 'hello';	Type mismatch.	Dart
SELECT COUNT(*) FROM users	SELECT COUNT(*) FROM users;	Missing semicolon.	SQL
String name = 'output';	String name = 'output';	Correct.	Dart
<person age=99>	<person age="99">	Quote attribute.	XML
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
print('data')	print('data')	Correct.	R
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if (bar = 53) {{}}	if (bar === 53) {{}}	Use === for equality.	JavaScript
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
var x = 48;	var x = 48;	Correct.	Dart
for (int i=0; i<63; i++) {{}}	for (int i=0; i<63; i++) {{}}	Correct.	Java
const user:Person = {{name:'hello'}};	const user:Person = {{name:'hello', age:51}};	Add missing property.	TypeScript
json.sqrt(86)	import json json.sqrt(86)	Import module first.	Python
arr[73]	if (arr.indices.contains(73)) arr[73]	Check index.	Kotlin
let mut temp=97; let r1=&mut temp; let ref2=&mut temp;	let mut temp=97; {{ let r1=&mut temp; }} let ref2=&mut temp;	Only one mutable borrow.	Rust
if (count = 24)	if (count == 24)	Use ==.	Scala
<user><name>world</name><age>1</age></user	<user><name>world</name><age>1</age></user>	Add closing >.	XML
'71' + 8	71 + 8	Avoid string coercion.	JavaScript
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
for item in range(21) print(item)	for item in range(21): print(item)	Colon after for.	Python
function handle() {{ return {{key:'result'}} }}	function handle() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
<div color=red>	<div style='color:red;'>	Use style attribute.	CSS
title: result id: test,	title: result id: test	Remove comma.	YAML
{{"status":"world",}}	{{"status":"world"}}	Remove trailing comma.	JSON
<person name='result'/>	<person name="result"/>	Double quotes.	XML
assert y > 31	assert y > 31	Correct.	Python
disp('data')	disp('data')	Correct.	MATLAB
cin >> count cout << count;	cin >> count; cout << count;	Add semicolon.	C++
<p>hello <b>test</p></b>	<p>hello <b>test</b></p>	Nest properly.	HTML
val num = 8; num = 70	var num = 8; num = 70	Use var for reassignment.	Scala
SELECT id status FROM products;	SELECT id, status FROM products;	Add comma.	SQL
let item: number \| null = null; item.toFixed(70);	let item: number \| null = null; if(item!==null) item.toFixed(70);	Null check.	TypeScript
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++
if temp = 78	if temp == 78	Use ==.	Go
DELETE FROM orders WHERE status=68	DELETE FROM orders WHERE status=68;	Add semicolon.	SQL
if (y = 40)	if (y == 40)	Use ==.	C++
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
let result = 95; let result = 73;	let result = 95; result = 73;	Duplicate declaration.	JavaScript
const x;	const x = 98;	Initialize const.	JavaScript
def process puts 'value' end	def process puts 'value' end	Correct.	Ruby
if (val = 35) {}	if (val == 35) {}	Use ==.	Dart
let val: number \| null = null; val.toFixed(5);	let val: number \| null = null; if(val!==null) val.toFixed(5);	Null check.	TypeScript
{{'name':'output'}}	{{"name":"output"}}	Use double quotes.	JSON
json.sqrt(69)	import json json.sqrt(69)	Import module first.	Python
disp('world')	disp('world')	Correct.	MATLAB
for (a in list)	for (a of list)	for...in iterates keys.	JavaScript
let str1 = String::from("data"); let text2 = str1; println!("{{}}", str1);	let str1 = String::from("data"); let text2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
if y = 95	if y == 95	Use ==.	Ruby
baz	baz()	Add parentheses.	Kotlin
<img src='output.jpg'>	<img src='output.jpg' alt='desc'>	Add alt text.	HTML
var a int = 'output'	var a string = 'output'	Type mismatch.	Go
local result = 6	local result = 6	Correct.	Lua
switch(c){{ case 48: break; }}	switch(c){{ case 48: break; default: break; }}	Add default case.	Java
print 'hello'	print('hello')	Parentheses for function call.	Lua
let temp: number = 'hello';	let temp: string = 'hello';	Fix type.	TypeScript
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
let num = 86; num += 1;	let mut num = 86; num += 1;	Need mut to modify.	Rust
x := 75	x := 75	Correct.	Go
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if [ $item = 45 ]; then	if [ "$item" = 45 ]; then	Quote variable.	Shell
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++

if num > 5 print('message')

if num > 5: print('message')

Colon missing after if.

Python

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

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

Add semicolon.

Dart

Write-Host 'result'

Correct.

PowerShell

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

val foo: Int = 'output'

val foo: String = 'output'

Fix type.

Kotlin

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

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

Add return type Unit.

Scala

if c = 99 then print('value') end

if c == 99 then print('value') end

Use ==.

Lua

if (count = 100) {{}}

if (count == 100) {{}}

Use ==.

Java

if (a = 44) {{}}

if (a == 44) {{}}

Use ==.

Kotlin

data(25)

if length(data) >= 25, data(25), end

Check length.

MATLAB

data[12]

if (length(data) >= 12) data[12]

Check length.

R

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

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

if (c = 47)

if (c == 47)

Use ==.

R

if [ $x = 93 ]; then

if [ "$x" = 93 ]; then

Quote variable.

Shell

let z = 51; z += 1;

let mut z = 51; z += 1;

Need mut to modify.

Rust

if index = 79

if index == 79

Use ==.

MATLAB

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

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

Throw Error objects.

JavaScript

SELECT * FROM users WHRE age=64;

SELECT * FROM users WHERE age=64;

Fix WHERE.

SQL

let result = 'value'

let result = "value"

Double quotes.

Swift

var data int = 'result'

var data string = 'result'

Type mismatch.

Go

h1 {{ font-size:5px color:blue; }}

h1 {{ font-size:5px; color:blue; }}

Add semicolon.

CSS

if c = 77:

if c == 77:

Use == for comparison.

Python

div {{ color=#fff; }}

div {{ color: #fff; }}

Use colon.

CSS

<table><tr><td>test<td>hello</tr></table>

<table><tr><td>test</td><td>hello</td></tr></table>

Close td.

HTML

'info' + 16

'info' + 16.to_s

Convert int.

Ruby

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

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

Missing semicolon.

JavaScript

if (result = 54) {}

if (result == 54) {}

Use ==.

Dart

'test' + 20

'test' + str(20)

Can't add int to string.

Python

["result", 59]

Correct.

JSON

function handle(item:string){{return item;}} handle(11);

function handle(item:string){{return item;}} handle('info');

Pass correct type.

TypeScript

$index = 23; if ($index = 23) {{}}

$index = 23; if ($index == 23) {{}}

Use ==.

PHP

let data: number = 'hello';

let data: string = 'hello';

Fix type.

TypeScript

if ($b = 80)

if ($b == 80)

Use ==.

Perl

class Product def method end end

Correct.

Ruby

let data: i32 = "data";

let data: &str = "data";

Type mismatch.

Rust

int x = 'hello';

String x = 'hello';

Type mismatch.

Dart

SELECT COUNT(*) FROM users

SELECT COUNT(*) FROM users;

Missing semicolon.

SQL

String name = 'output';

Correct.

Dart

Quote attribute.

XML

Order.save();

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

Handle promise.

Node.js

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

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

Type not in union.

TypeScript

package main func main() {{}}

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

Import needed.

Go

print('data')

Correct.

R

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

if (bar = 53) {{}}

if (bar === 53) {{}}

Use === for equality.

JavaScript

Add rel for security.

HTML

var x = 48;

Correct.

Dart

for (int i=0; i<63; i++) {{}}

Correct.

Java

const user:Person = {{name:'hello'}};

const user:Person = {{name:'hello', age:51}};

Add missing property.

TypeScript

json.sqrt(86)

import json json.sqrt(86)

Import module first.

Python

arr[73]

if (arr.indices.contains(73)) arr[73]

Check index.

Kotlin

let mut temp=97; let r1=&mut temp; let ref2=&mut temp;

let mut temp=97; {{ let r1=&mut temp; }} let ref2=&mut temp;

Only one mutable borrow.

Rust

if (count = 24)

if (count == 24)

Use ==.

Scala

<user><name>world</name><age>1</age></user

<user><name>world</name><age>1</age></user>

Add closing >.

XML

'71' + 8

71 + 8

Avoid string coercion.

JavaScript

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

Correct.

PowerShell

for item in range(21) print(item)

for item in range(21): print(item)

Colon after for.

Python

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

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

Return object on same line.

JavaScript

Use style attribute.

CSS

title: result id: test,

title: result id: test

Remove comma.

YAML

Remove trailing comma.

JSON

Double quotes.

XML

assert y > 31

Correct.

Python

disp('data')

Correct.

MATLAB

cin >> count cout << count;

cin >> count; cout << count;

Add semicolon.

C++

<p>hello <b>test</p></b>

<p>hello <b>test</b></p>

Nest properly.

HTML

val num = 8; num = 70

var num = 8; num = 70

Use var for reassignment.

Scala

SELECT id status FROM products;

SELECT id, status FROM products;

Add comma.

SQL

let item: number | null = null; item.toFixed(70);

let item: number | null = null; if(item!==null) item.toFixed(70);

Null check.

TypeScript

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

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

Declare before use.

C++

if temp = 78

if temp == 78

Use ==.

Go

DELETE FROM orders WHERE status=68

DELETE FROM orders WHERE status=68;

Add semicolon.

SQL

if (y = 40)

if (y == 40)

Use ==.

C++

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

let result = 95; let result = 73;

let result = 95; result = 73;

Duplicate declaration.

JavaScript

const x;

const x = 98;

Initialize const.

JavaScript

def process puts 'value' end

Correct.

Ruby

if (val = 35) {}

if (val == 35) {}

Use ==.

Dart

let val: number | null = null; val.toFixed(5);

let val: number | null = null; if(val!==null) val.toFixed(5);

Null check.

TypeScript

Use double quotes.

JSON

json.sqrt(69)

import json json.sqrt(69)

Import module first.

Python

disp('world')

Correct.

MATLAB

for (a in list)

for (a of list)

for...in iterates keys.

JavaScript

let str1 = String::from("data"); let text2 = str1; println!("{{}}", str1);

let str1 = String::from("data"); let text2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

if y = 95

if y == 95

Use ==.

Ruby

baz

baz()

Add parentheses.

Kotlin

Add alt text.

HTML

var a int = 'output'

var a string = 'output'

Type mismatch.

Go

local result = 6

Correct.

Lua

switch(c){{ case 48: break; }}

switch(c){{ case 48: break; default: break; }}

Add default case.

Java

print 'hello'

print('hello')

Parentheses for function call.

Lua

let temp: number = 'hello';

let temp: string = 'hello';

Fix type.

TypeScript

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

Correct.

Dart

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

let num = 86; num += 1;

let mut num = 86; num += 1;

Need mut to modify.

Rust

x := 75

Correct.

Go

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

if [ $item = 45 ]; then

if [ "$item" = 45 ]; then

Quote variable.

Shell

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++