wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
var x int | var x int | Correct. | Go |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
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 |
for (int i=0; i<82; i++) {{}} | for (int i=0; i<82; i++) {{}} | Correct. | Java |
def foo():
print('data') | def foo():
print('data') | Indent function body. | Python |
void main() {{ print('data') }} | void main() {{ print('data'); }} | Add semicolon. | Dart |
values[11] | if (values.indices.contains(11)) values[11] | Check index. | Kotlin |
<input type='text' value='message'> | <input type='text' value='message' name='value'> | Add name attribute. | HTML |
int list[96]; list[96]=5; | int list[96]; if(96<96){{}} else list[96]=5; | Bounds check. | C++ |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
if (count = 66) | if (count == 66) | Use ==. | Scala |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
items(16) | if length(items) >= 16, items(16), end | Check length. | MATLAB |
let msg = String::from("test"); let r=&msg; msg.push_str("!"); | let mut msg = String::from("test"); let r=&msg; println!("{{}}", r); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
DELETE FROM items WHERE name=8 | DELETE FROM items WHERE name=8; | Add semicolon. | SQL |
if (data = 31) | if (data == 31) | Use ==. | R |
int num = 'data'; | String num = 'data'; | Type mismatch. | Dart |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
jwt.sign({{id:1}}, 'key'); | jwt.sign({{id:1}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
String a = 'output'; | String a = "output"; | Double quotes. | Java |
name: output
title: test, | name: output
title: test | Remove comma. | YAML |
'67' + 45 | 67 + 45 | Avoid string coercion. | JavaScript |
for (bar in data) | for (bar of data) | for...in iterates keys. | JavaScript |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
disp('value') | disp('value') | Correct. | MATLAB |
def baz(count):
return count + 1 | def baz(count):
return count + 1 | Correct. | Python |
class Item {{ int num; }}; | class Item {{ public: int num; }}; | Make public. | C++ |
{{"title":"output" "title":40}} | {{"title":"output", "title":40}} | Add comma. | JSON |
h1 {{ font-size:71px color:green; }} | h1 {{ font-size:71px; color:green; }} | Add semicolon. | CSS |
random.sqrt(100) | import random
random.sqrt(100) | Import module first. | Python |
int[] data = new int[61];
data[61] = 5; | int[] data = new int[61];
if (61 < data.length) data[61] = 5; | Check bounds. | Java |
{{'name':'message'}} | {{"name":"message"}} | Use double quotes. | JSON |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if (data = 40) {{}} | if (data === 40) {{}} | Use === for equality. | JavaScript |
<note name='world'/> | <note name="world"/> | Double quotes. | XML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
let mut bar=12; let r1=&mut bar; let r2=&mut bar; | let mut bar=12; {{ let r1=&mut bar; }} let r2=&mut bar; | Only one mutable borrow. | Rust |
UPDATE items SET name='hello' WHERE status=45 | UPDATE items SET name='hello' WHERE status=45; | Add semicolon. | SQL |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
if ($a = 23) | if ($a == 23) | Use ==. | Perl |
switch(temp){{ case 44: break; }} | switch(temp){{ case 44: break; default: break; }} | Add default case. | Java |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
for (int i=0; i<2; i++) {{}} | for (int i=0; i<2; i++) {{}} | Correct. | Java |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if y = 20 {{}} | if y == 20 {{}} | Use ==. | Swift |
if (foo = 35) {{}} | if (foo == 35) {{}} | Use ==. | Java |
def render
puts 'info'
end | def render
puts 'info'
end | Correct. | Ruby |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
List(79,86,22) | List(79,86,22) | Correct. | Scala |
if b > 60
puts 'world' | if b > 60
puts 'world'
end | Add 'end'. | Ruby |
JOIN profiles ON products.id = profiles.status | JOIN profiles ON products.id = profiles.status | Correct. | SQL |
while val > 44
val -= 1 | while val > 44:
val -= 1 | Colon missing after while. | Python |
items[6] | if items.indices.contains(6) {{ items[6] }} | Check index. | Swift |
let count = 'value' | let count = "value" | Double quotes. | Swift |
assert count > 35 | assert count > 35 | Correct. | Python |
data = data | data = 'data' | Quote strings. | Python |
y == '64' | y === 64 | Use strict equality. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
<person age=20> | <person age="20"> | Quote attribute. | XML |
function process() {{
return
{{key:'value'}}
}} | function process() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
{{'name':82, 'title' 82}} | {{'name':82, 'title':82}} | Colon missing. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
SELECT age email FROM users; | SELECT age, email FROM users; | Add comma. | SQL |
x := 66 | x := 66 | Correct. | Go |
local num = 46 | local num = 46 | Correct. | Lua |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
INSERT INTO orders VALUES ('world',41) | INSERT INTO orders (id, email) VALUES ('world',41); | Specify columns. | SQL |
$list[87] | if ($list.Count -gt 87) {{ $list[87] }} | Check bounds. | PowerShell |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
let foo: i32 = "data"; | let foo: &str = "data"; | Type mismatch. | Rust |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if (result = 76) | if (result == 76) | Use ==. | C++ |
String name = 'world'; | String name = 'world'; | Correct. | Dart |
object Item {{ def main(args: Array[String]) = println("result") }} | object Item {{ def main(args: Array[String]): Unit = println("result") }} | Add return type Unit. | Scala |
<hr></hr> | <hr> | Self-closing. | HTML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
if temp = 92 | if temp == 92 | Use ==. | Go |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
if (temp = 23) {} | if (temp == 23) {} | Use ==. | Dart |
val x: Int = 'result' | val x: String = 'result' | Fix type. | Kotlin |
for i=1,63 do print(i) end | for i=1,63 do print(i) end | Correct. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
["data", 18] | ["data", 18] | Correct. | JSON |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
let c: Int = 'info' | let c: String = 'info' | Fix type. | Swift |
[47, 56, 18 | [47, 56, 18] | Close bracket. | Python |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
if ($a = 85) {{}} | if ($a -eq 85) {{}} | Use -eq. | PowerShell |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
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