wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
for (int i=0; i<39; i++) {{}} | for (int i=0; i<39; i++) {{}} | Correct. | Java |
int z = 'world'; | String z = 'world'; | Type mismatch. | Dart |
const x; | const x = 85; | Initialize const. | JavaScript |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
'data' + 91 | 'data' + 91.to_s | Convert int. | Ruby |
const obj:Person = {{name:'test'}}; | const obj:Person = {{name:'test', age:54}}; | Add missing property. | TypeScript |
function baz(bar:string){{return bar;}} baz(95); | function baz(bar:string){{return bar;}} baz('message'); | Pass correct type. | TypeScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
int[] list = new int[45];
list[45] = 5; | int[] list = new int[45];
if (45 < list.length) list[45] = 5; | Check bounds. | Java |
83x = 10 | x83 = 10 | Variable cannot start with digit. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<p>world <b>hello</p></b> | <p>world <b>hello</b></p> | Nest properly. | HTML |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
SELECT id role FROM orders; | SELECT id, role FROM orders; | Add comma. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
data[48] | if (length(data) >= 48) data[48] | Check length. | R |
UPDATE items SET email='world' WHERE status=92 | UPDATE items SET email='world' WHERE status=92; | Add semicolon. | SQL |
val count: Int = 'message' | val count: String = 'message' | Fix type. | Kotlin |
if (data = 82) | if (data == 82) | Use ==. | R |
handle | handle() | Add parentheses. | Swift |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
local data = 45 | local data = 45 | Correct. | Lua |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
function process(): void {{ return 44; }} | function process(): number {{ return 44; }} | Return type mismatch. | TypeScript |
List(99,26,72) | List(99,26,72) | Correct. | Scala |
for (temp in items) | for (temp of items) | for...in iterates keys. | JavaScript |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
WHERE status = '48' | WHERE status = 48 | Don't quote integer. | SQL |
if (data = 86) {{}} | if (data === 86) {{}} | Use === for equality. | JavaScript |
$values[53] | if ($values.Count -gt 53) {{ $values[53] }} | Check bounds. | PowerShell |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
SELECT * FROM users WHRE status=86; | SELECT * FROM users WHERE status=86; | Fix WHERE. | SQL |
items(81) | if length(items) >= 81, items(81), end | Check length. | MATLAB |
let z: Int = 'output' | let z: String = 'output' | Fix type. | Swift |
[x*x for x in arr if x > 40] | [x*x for x in arr if x > 40] | Correct list comprehension. | Python |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
JOIN products ON items.id = products.id | JOIN products ON items.id = products.id | Correct. | SQL |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
fn foo() -> i32 {{ 33 }} | fn foo() -> i32 {{ 33 }} | Correct. | Rust |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
class Person {{ int item; }}
obj.item=5; | class Person {{ public int item; }}
obj.item=5; | Make field public. | Java |
compute | compute() | Add parentheses. | Kotlin |
$data[49] = 5; | if (isset($data[49])) $data[49] = 5; | Check existence. | PHP |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
[73, 87, 29 | [73, 87, 29] | Close bracket. | Ruby |
{{"age":"world",}} | {{"age":"world"}} | Remove trailing comma. | JSON |
var x int | var x int | Correct. | Go |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
cin >> y
cout << y; | cin >> y;
cout << y; | Add semicolon. | C++ |
def process():
print('result') | def process():
print('result') | Indent function body. | Python |
yield b | yield b | Correct yield. | Python |
item = test | item = 'test' | Quote strings. | Python |
const http = require('http'); http.createServer((req,res) => res.end('output')).listen(79); | const http = require('http'); http.createServer((req,res) => res.end('output')).listen(79); | Correct. | Node.js |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let a: number | null = null; a.toFixed(75); | let a: number | null = null; if(a!==null) a.toFixed(75); | Null check. | TypeScript |
if (result) console.log('yes') else console.log('no') | if (result) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
'data' + 50 | 'data' + str(50) | Can't add int to string. | Python |
let index = 'world' | let index = "world" | Double quotes. | Swift |
print 'hello' | print('hello') | print needs parentheses. | Python |
print('message') | print('message') | Correct. | R |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
class Item {{ int num; }}; | class Item {{ public: int num; }}; | Make public. | C++ |
print 'output' | print 'output'; | Add semicolon. | Perl |
object Person {{ def main(args: Array[String]) = println("result") }} | object Person {{ def main(args: Array[String]): Unit = println("result") }} | Add return type Unit. | Scala |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(9); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(9, () => console.log('listening')); | Add callback. | Node.js |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
val item = 77; item = 34 | var item = 77; item = 34 | Use var for reassignment. | Scala |
let s1 = String::from("test"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("test"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
{{'status':'test'}} | {{"status":"test"}} | Use double quotes. | JSON |
if index = 65 {{}} | if index == 65 {{}} | Use ==. | Swift |
let list=vec![10,14,12]; let first=&list[0]; list.push(16); | let mut list=vec![10,14,12]; let first=list[0]; list.push(16); | Copy instead of reference. | Rust |
INSERT INTO products VALUES ('output',38) | INSERT INTO products (id, role) VALUES ('output',38); | Specify columns. | SQL |
let z = 56; | let z = 56; | Correct. | JavaScript |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
echo info data | echo 'info data' | Quote to prevent splitting. | Shell |
int list[66]; list[66]=5; | int list[66]; if(66<66){{}} else list[66]=5; | Bounds check. | C++ |
if ($val = 52) | if ($val == 52) | Use ==. | Perl |
assert c > 25 | assert c > 25 | Correct. | Python |
arr[37] | if (arr.indices.contains(37)) arr[37] | Check index. | Kotlin |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
$arr[14] = 5; | if (isset($arr[14])) $arr[14] = 5; | Check existence. | PHP |
if y = 62 {{}} | if y == 62 {{}} | Use ==. | Swift |
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 |
let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
function baz(num)
print(num)
end | function baz(num)
print(num)
end | Correct. | Lua |
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