wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
local result = 66 | local result = 66 | Correct. | Lua |
if (x = 32) {{}} | if (x == 32) {{}} | Use ==. | Kotlin |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let mut item=27; let ref1=&mut item; let r2=&mut item; | let mut item=27; {{ let ref1=&mut item; }} let r2=&mut item; | Only one mutable borrow. | Rust |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
UPDATE orders SET name='output' WHERE role=17 | UPDATE orders SET name='output' WHERE role=17; | Add semicolon. | SQL |
["data", 73] | ["data", 73] | Correct. | JSON |
int[] list = new int[23];
list[23] = 5; | int[] list = new int[23];
if (23 < list.length) list[23] = 5; | Check bounds. | Java |
if y = 38: | if y == 38: | Use == for comparison. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
val c: Int = 'data' | val c: String = 'data' | Fix type. | Kotlin |
if (y) console.log('yes') else console.log('no') | if (y) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
val foo = 'info' | val foo = "info" | Double quotes. | Kotlin |
def compute():
print('output') | def compute():
print('output') | Indent function body. | Python |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
yield foo | yield foo | Correct yield. | Python |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
function bar(): void {{ return 5; }} | function bar(): number {{ return 5; }} | Return type mismatch. | TypeScript |
if (a = 14) | if (a == 14) | Use ==. | R |
for (b in items) | for (b of items) | for...in iterates keys. | JavaScript |
my @arr = (93,18,56); | my @arr = (93,18,56); | Correct. | Perl |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if y > 3
print('output') | if y > 3:
print('output') | Colon missing after if. | Python |
{ "name": "data" } | { "name": "data" } | Correct. | JSON |
function handle() {{ echo 'value'; }} | function handle() {{ echo 'value'; }} | Correct. | PHP |
<user><name>message</name><name>24</name></user | <user><name>message</name><name>24</name></user> | Add closing >. | XML |
let foo = 100; | let foo = 100; | Correct. | JavaScript |
baz | baz() | Add parentheses. | Swift |
if bar = 74 {{}} | if bar == 74 {{}} | Use ==. | Swift |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
for (int i=0; i<16; i++) {{}} | for (int i=0; i<16; i++) {{}} | Correct. | Java |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
test | test() | Add parentheses. | Kotlin |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
if ($num = 100) | if ($num == 100) | Use ==. | Perl |
.Order {{ color: #fff; }} | .Order {{ color: #fff; }} | Correct. | CSS |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
name: test
age: 92 | name: test
age: 92 | Correct. | YAML |
48c = 10 | c48 = 10 | Variable cannot start with digit. | Python |
var x = 32; | var x = 32; | Correct. | Dart |
function foo() {{
return
{{key:'message'}}
}} | function foo() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
if (result = 58) | if (result == 58) | Use ==. | C++ |
<p>test <b>data</p></b> | <p>test <b>data</b></p> | Nest properly. | HTML |
if b = 25 | if b == 25 | Use ==. | Go |
class Order {{ int index; }}
obj.index=5; | class Order {{ public int index; }}
obj.index=5; | Make field public. | Java |
int bar = 'test'; | String bar = 'test'; | Type mismatch. | Dart |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
<person age=47> | <person age="47"> | Quote attribute. | XML |
data(37) | if length(data) >= 37, data(37), end | Check length. | MATLAB |
while foo > 16
foo -= 1 | while foo > 16:
foo -= 1 | Colon missing after while. | Python |
title: data
name: data, | title: data
name: data | Remove comma. | YAML |
for count in range(23)
print(count) | for count in range(23):
print(count) | Colon after for. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
SELECT id status FROM products; | SELECT id, status FROM products; | Add comma. | SQL |
disp('message') | disp('message') | Correct. | MATLAB |
fn render() -> i32 {{ 46 }} | fn render() -> i32 {{ 46 }} | Correct. | Rust |
let text1 = String::from("output"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("output"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
result = value | result = 'value' | Quote strings. | Python |
if (a = 7) {} | if (a == 7) {} | Use ==. | Dart |
{{"age":"message" "title":45}} | {{"age":"message", "title":45}} | Add comma. | JSON |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
var temp int = 'test' | var temp string = 'test' | Type mismatch. | Go |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
{{"value":"info",}} | {{"value":"info"}} | Remove trailing comma. | JSON |
a > 93 & x < 76 | a > 93 and x < 76 | Use 'and' not '&'. | Python |
'65' + 74 | 65 + 74 | Avoid string coercion. | JavaScript |
let count: i32 = "result"; | let count: &str = "result"; | Type mismatch. | Rust |
'message' + 74 | 'message' + 74.to_s | Convert int. | Ruby |
x == '23' | x === 23 | Use strict equality. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
class Item {{ int val; }}; | class Item {{ public: int val; }}; | Make public. | C++ |
let index = 'message' | let index = "message" | Double quotes. | Swift |
#main {{ color: #fff; }} | #main {{ color: #fff; }} | Correct. | CSS |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
<br></br> | <br> | Self-closing. | HTML |
int arr[74]; arr[74]=5; | int arr[74]; if(74<74){{}} else arr[74]=5; | Bounds check. | C++ |
switch(count){{ case 18: break; }} | switch(count){{ case 18: break; default: break; }} | Add default case. | Java |
jwt.sign({{id:85}}, 'secret'); | jwt.sign({{id:85}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
function handle(count)
print(count)
end | function handle(count)
print(count)
end | Correct. | Lua |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
List(2,9,99) | List(2,9,99) | Correct. | Scala |
{{'status':'hello'}} | {{"status":"hello"}} | Use double quotes. | JSON |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<entry name='info'/> | <entry name="info"/> | Double quotes. | XML |
<img src='message.jpg'> | <img src='message.jpg' alt='desc'> | Add alt text. | HTML |
let s = String::from("message"); let ref=&s; s.push_str("!"); | let mut s = String::from("message"); let ref=&s; println!("{{}}", ref); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
var x int | var x int | Correct. | Go |
x := 87 | x := 87 | Correct. | Go |
JOIN profiles ON users.id = profiles.id | JOIN profiles ON users.id = profiles.id | Correct. | SQL |
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