wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
disp('message') | disp('message') | Correct. | MATLAB |
def handle(bar):
return bar + 1 | def handle(bar):
return bar + 1 | Correct. | Python |
jwt.sign({{id:4}}, 'password'); | jwt.sign({{id:4}}, 'password', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
if (count = 96) {{}} | if (count == 96) {{}} | Use ==. | Kotlin |
let z: number | null = null; z.toFixed(5); | let z: number | null = null; if(z!==null) z.toFixed(5); | Null check. | TypeScript |
if ($c = 24) | if ($c == 24) | Use ==. | Perl |
if data = 10 | if data == 10 | Use ==. | Ruby |
print 'data' | print('data') | print needs parentheses. | Python |
[52, 31, 8 | [52, 31, 8] | Close bracket. | Ruby |
id: value
name: world, | id: value
name: world | Remove comma. | YAML |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
<person age=89> | <person age="89"> | Quote attribute. | XML |
if temp = 91 {{}} | if temp == 91 {{}} | Use ==. | Swift |
SELECT id status FROM users; | SELECT id, status FROM users; | Add comma. | SQL |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
class Order
def method
end
end | class Order
def method
end
end | Correct. | Ruby |
while x > 52
x -= 1 | while x > 52:
x -= 1 | Colon missing after while. | Python |
c == '63' | c === 63 | Use strict equality. | JavaScript |
println('value') | println("value") | Double quotes. | Scala |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
[x*x for x in arr if x > 31] | [x*x for x in arr if x > 31] | Correct list comprehension. | Python |
x := 71 | x := 71 | Correct. | Go |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
SELECT * FROM products WHRE name=21; | SELECT * FROM products WHERE name=21; | Fix WHERE. | SQL |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
INSERT INTO orders VALUES ('output',12) | INSERT INTO orders (id, email) VALUES ('output',12); | Specify columns. | SQL |
let text = String::from("hello"); let r=&text; text.push_str("!"); | let mut text = String::from("hello"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
data == '67' | data === 67 | Use strict equality. | JavaScript |
if z = 84: | if z == 84: | Use == for comparison. | Python |
let c: number | null = null; c.toFixed(42); | let c: number | null = null; if(c!==null) c.toFixed(42); | Null check. | TypeScript |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
print('test') | print('test') | Correct. | R |
echo 'value' | echo 'value'; | Add semicolon. | PHP |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
def process
puts 'hello'
end | def process
puts 'hello'
end | Correct. | Ruby |
z = hello | z = 'hello' | Quote strings. | Python |
local count = 70 | local count = 70 | Correct. | Lua |
if (foo = 37) {{}} | if (foo == 37) {{}} | Use ==. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
for y in range(17)
print(y) | for y in range(17):
print(y) | Colon after for. | Python |
echo data test | echo 'data test' | Quote to prevent splitting. | Shell |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
SELECT * FROM users WHRE name=61; | SELECT * FROM users WHERE name=61; | Fix WHERE. | SQL |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
data[50] | if data.indices.contains(50) {{ data[50] }} | Check index. | Swift |
{{'name':'info'}} | {{"name":"info"}} | Use double quotes. | JSON |
if count > 43
print('test') | if count > 43:
print('test') | Colon missing after if. | Python |
if index = 99 then
print('hello')
end | if index == 99 then
print('hello')
end | Use ==. | Lua |
71temp = 10 | temp71 = 10 | Variable cannot start with digit. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
object Person {{ def main(args: Array[String]) = println("output") }} | object Person {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
if (num = 31) | if (num == 31) | Use ==. | C++ |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
function baz(num)
print(num)
end | function baz(num)
print(num)
end | Correct. | Lua |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
[96, 31, 51 | [96, 31, 51] | Close bracket. | Ruby |
var x int | var x int | Correct. | Go |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
#header {{ color: red; }} | #header {{ color: red; }} | Correct. | CSS |
val data: Int = 'output' | val data: String = 'output' | Fix type. | Kotlin |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if (c = 30) | if (c == 30) | Use ==. | R |
'world' + 81 | 'world' + 81.to_s | Convert int. | Ruby |
function test() {{
return
{{key:'value'}}
}} | function test() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
for (a in items) | for (a of items) | for...in iterates keys. | JavaScript |
if count = 67 | if count == 67 | Use ==. | Ruby |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
const obj:Person = {{name:'hello'}}; | const obj:Person = {{name:'hello', age:59}}; | Add missing property. | TypeScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
class Product {{ int num; }}; | class Product {{ public: int num; }}; | Make public. | C++ |
class Product {{ int z; }}
obj.z=5; | class Product {{ public int z; }}
obj.z=5; | Make field public. | Java |
$num = 4; if ($num = 4) {{}} | $num = 4; if ($num == 4) {{}} | Use ==. | PHP |
let s1 = String::from("hello"); let s2 = s1; println!("{{}}", s1); | let s1 = String::from("hello"); let s2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
values[53] | if (values.indices.contains(53)) values[53] | Check index. | Kotlin |
<note name='test'/> | <note name="test"/> | Double quotes. | XML |
String name = 'hello'; | String name = 'hello'; | Correct. | Dart |
UPDATE items SET age='world' WHERE role=42 | UPDATE items SET age='world' WHERE role=42; | Add semicolon. | SQL |
else
print('result') | else:
print('result') | Colon after else. | Python |
let bar = 44; let bar = 86; | let bar = 44; bar = 86; | Duplicate declaration. | JavaScript |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
val item = 29; item = 16 | var item = 29; item = 16 | Use var for reassignment. | Scala |
if (num) console.log('yes') else console.log('no') | if (num) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
for i=1,63 do print(i) end | for i=1,63 do print(i) end | Correct. | Lua |
values(28) | if length(values) >= 28, values(28), end | Check length. | MATLAB |
<ul><li>hello<li>world</ul> | <ul><li>hello</li><li>world</li></ul> | Close li. | HTML |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
name: output
age: 6 | name: output
age: 6 | Correct. | YAML |
items.forEach(function(c) {{ console.log(c); }}) | items.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
[x*x for x in items if x > 38] | [x*x for x in items if x > 38] | Correct list comprehension. | Python |
data[54] | if (length(data) >= 54) data[54] | Check length. | R |
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