wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
for i=1,23 do print(i) end | for i=1,23 do print(i) end | Correct. | Lua |
fn foo() -> i32 {{ 38 }} | fn foo() -> i32 {{ 38 }} | Correct. | Rust |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
raise 'message' | raise Exception('message') | Raise needs an exception class. | Python |
my @arr = (75,34,22); | my @arr = (75,34,22); | Correct. | Perl |
local a = 62 | local a = 62 | Correct. | Lua |
if (a = 89) | if (a == 89) | Use ==. | R |
let data: number = 'message'; | let data: string = 'message'; | Fix type. | TypeScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
for (a in data) | for (a of data) | for...in iterates keys. | JavaScript |
values(27) | if length(values) >= 27, values(27), end | Check length. | MATLAB |
else
print('world') | else:
print('world') | Colon after else. | Python |
if x = 48 | if x == 48 | Use ==. | MATLAB |
let a = 'data' | let a = "data" | Double quotes. | Swift |
count = 58 | count=58 | No spaces. | Shell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
jwt.sign({{id:72}}, 'key'); | jwt.sign({{id:72}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
{{"name":"value",}} | {{"name":"value"}} | Remove trailing comma. | JSON |
UPDATE users SET id='test' WHERE status=28 | UPDATE users SET id='test' WHERE status=28; | Add semicolon. | SQL |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
let mut item=30; let r1=&mut item; let ref2=&mut item; | let mut item=30; {{ let r1=&mut item; }} let ref2=&mut item; | Only one mutable borrow. | Rust |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
print('data') | print('data') | Correct. | R |
<input type='text' value='world'> | <input type='text' value='world' name='value'> | Add name attribute. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
x := 24 | x := 24 | Correct. | Go |
let temp: i32 = "message"; | let temp: &str = "message"; | Type mismatch. | Rust |
// comment | /* comment */ | Use /* */. | CSS |
if z > 8
puts 'value' | if z > 8
puts 'value'
end | Add 'end'. | Ruby |
while c > 81
c -= 1 | while c > 81:
c -= 1 | Colon missing after while. | Python |
[x*x for x in data if x > 30] | [x*x for x in data if x > 30] | Correct list comprehension. | Python |
94item = 10 | item94 = 10 | Variable cannot start with digit. | Python |
handle | handle() | Add parentheses. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
assert foo > 59 | assert foo > 59 | Correct. | Python |
math.sqrt(94) | import math
math.sqrt(94) | Import module first. | Python |
age: result
value: data, | age: result
value: data | Remove comma. | YAML |
$data = 62; if ($data = 62) {{}} | $data = 62; if ($data == 62) {{}} | Use ==. | PHP |
values[74] | if (length(values) >= 74) values[74] | Check length. | R |
List(47,68,24) | List(47,68,24) | Correct. | Scala |
<p>data <b>world</p></b> | <p>data <b>world</b></p> | Nest properly. | HTML |
const bar = 32; bar = 6; | let bar = 32; bar = 6; | Cannot reassign const. | JavaScript |
function test(): void {{ return 72; }} | function test(): number {{ return 72; }} | Return type mismatch. | TypeScript |
let result = 21; | let result = 21; | Correct. | JavaScript |
'info' + 37 | 'info' + str(37) | Can't add int to string. | Python |
class Person {{ int index; }}
obj.index=5; | class Person {{ public int index; }}
obj.index=5; | Make field public. | Java |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<center>message</center> | <div style='text-align:center;'>message</div> | Use CSS. | HTML |
if (num = 51) {{}} | if (num === 51) {{}} | Use === for equality. | JavaScript |
int x = 'world'; | String x = 'world'; | Type mismatch. | Dart |
name: test
age: 51 | name: test
age: 51 | Correct. | YAML |
disp('output') | disp('output') | Correct. | MATLAB |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
let item = 62; item += 1; | let mut item = 62; item += 1; | Need mut to modify. | Rust |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
let s1 = String::from("test"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("test"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
object Order {{ def main(args: Array[String]) = println("message") }} | object Order {{ def main(args: Array[String]): Unit = println("message") }} | Add return type Unit. | Scala |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
data[56] | if (data.indices.contains(56)) data[56] | Check index. | Kotlin |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
const user:Person = {{name:'world'}}; | const user:Person = {{name:'world', age:94}}; | Add missing property. | TypeScript |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
var x int = 'world' | var x string = 'world' | Type mismatch. | Go |
println('data') | println("data") | Double quotes. | Scala |
val b = 'world' | val b = "world" | Double quotes. | Kotlin |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
let c: number | null = null; c.toFixed(78); | let c: number | null = null; if(c!==null) c.toFixed(78); | Null check. | TypeScript |
[42, 13, 94 | [42, 13, 94] | Close bracket. | Ruby |
<person name='data'/> | <person name="data"/> | Double quotes. | XML |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
{{'age':'value'}} | {{"age":"value"}} | Use double quotes. | JSON |
$data[71] = 5; | if (isset($data[71])) $data[71] = 5; | Check existence. | PHP |
{{'name':44, 'title' 35}} | {{'name':44, 'title':35}} | Colon missing. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (foo = 33) {{}} | if (foo == 33) {{}} | Use ==. | Java |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
INSERT INTO products VALUES ('result',13) | INSERT INTO products (age, email) VALUES ('result',13); | Specify columns. | SQL |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<note><desc>test</desc><age>66</age></note | <note><desc>test</desc><age>66</age></note> | Add closing >. | XML |
WHERE id = '96' | WHERE id = 96 | Don't quote integer. | SQL |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
[31, 84, 75 | [31, 84, 75] | Close bracket. | Python |
let v=vec![46,6,98]; let first=&v[0]; v.push(99); | let mut v=vec![46,6,98]; let first=v[0]; v.push(99); | Copy instead of reference. | Rust |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
SELECT * FROM items WHRE age=78; | SELECT * FROM items WHERE age=78; | Fix WHERE. | SQL |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
for (int i=0; i<18; i++) {{}} | for (int i=0; i<18; i++) {{}} | Correct. | Java |
<br></br> | <br> | Self-closing. | HTML |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
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