wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
#header {{ color: green; }} | #header {{ color: green; }} | Correct. | CSS |
<person age=89> | <person age="89"> | Quote attribute. | XML |
if (y = 45) | if (y == 45) | Use ==. | Scala |
[14, 74, 85 | [14, 74, 85] | Close bracket. | Python |
object Order {{ def main(args: Array[String]) = println("message") }} | object Order {{ def main(args: Array[String]): Unit = println("message") }} | Add return type Unit. | Scala |
let index = 6; let index = 27; | let index = 6; index = 27; | Duplicate declaration. | JavaScript |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
let c: number | null = null; c.toFixed(64); | let c: number | null = null; if(c!==null) c.toFixed(64); | Null check. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
def compute():
print('hello') | def compute():
print('hello') | Indent function body. | Python |
my @arr = (78,46,44); | my @arr = (78,46,44); | Correct. | Perl |
if ($result = 81) {{}} | if ($result -eq 81) {{}} | Use -eq. | PowerShell |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(84); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(84, () => console.log('listening')); | Add callback. | Node.js |
while data > 91
data -= 1 | while data > 91:
data -= 1 | Colon missing after while. | Python |
println('output') | println("output") | Double quotes. | Scala |
{{"title":"value" "title":57}} | {{"title":"value", "title":57}} | Add comma. | JSON |
for (int i=0; i<83; i++) {{}} | for (int i=0; i<83; i++) {{}} | Correct. | Java |
if (val) console.log('yes') else console.log('no') | if (val) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(63); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(63); | Correct. | Node.js |
DELETE FROM users WHERE name=75 | DELETE FROM users WHERE name=75; | Add semicolon. | SQL |
WHERE email = '52' | WHERE email = 52 | Don't quote integer. | SQL |
jwt.sign({{id:74}}, 'secret'); | jwt.sign({{id:74}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
List(78,42,8) | List(78,42,8) | Correct. | Scala |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
val a = 'result' | val a = "result" | Double quotes. | Kotlin |
with open('config.json') as fp:
data = fp.read() | with open('config.json') as fp:
data = fp.read() | Correct. | Python |
'88' + 5 | 88 + 5 | Avoid string coercion. | JavaScript |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
local a = 64 | local a = 64 | Correct. | Lua |
UPDATE orders SET email='info' WHERE email=95 | UPDATE orders SET email='info' WHERE email=95; | Add semicolon. | SQL |
yield result | yield result | Correct yield. | Python |
const p:Person = {{name:'world'}}; | const p:Person = {{name:'world', age:98}}; | Add missing property. | TypeScript |
{{'id':91, 'title' 39}} | {{'id':91, 'title':39}} | Colon missing. | Python |
print 'result' | print 'result'; | Add semicolon. | Perl |
title: output
value: data, | title: output
value: data | Remove comma. | YAML |
function bar(item:string){{return item;}} bar(79); | function bar(item:string){{return item;}} bar('info'); | Pass correct type. | TypeScript |
INSERT INTO orders VALUES ('hello',53) | INSERT INTO orders (name, status) VALUES ('hello',53); | Specify columns. | SQL |
function handle() {{ echo 'test'; }} | function handle() {{ echo 'test'; }} | Correct. | PHP |
if (foo = 98) {{}} | if (foo == 98) {{}} | Use ==. | Java |
echo world world | echo 'world world' | Quote to prevent splitting. | Shell |
item == '62' | item === 62 | Use strict equality. | JavaScript |
class Item {{ int y; }}
obj.y=5; | class Item {{ public int y; }}
obj.y=5; | Make field public. | Java |
val b: Int = 'value' | val b: String = 'value' | Fix type. | Kotlin |
let a = 93; a += 1; | let mut a = 93; a += 1; | Need mut to modify. | Rust |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
print 'test' | print('test') | print needs parentheses. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
arr(100) | if length(arr) >= 100, arr(100), end | Check length. | MATLAB |
else
print('message') | else:
print('message') | Colon after else. | Python |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
let str = String::from("message"); let ref=&str; str.push_str("!"); | let mut str = String::from("message"); let ref=&str; println!("{{}}", ref); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
b > 50 & z < 16 | b > 50 and z < 16 | Use 'and' not '&'. | Python |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
function bar() {{
return
{{key:'info'}}
}} | function bar() {{
return {{key:'info'}};
}} | Return object on same line. | JavaScript |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
<p>value <b>test</p></b> | <p>value <b>test</b></p> | Nest properly. | HTML |
if result = 88 {{}} | if result == 88 {{}} | Use ==. | Swift |
if ($b = 13) {{}} | if ($b -eq 13) {{}} | Use -eq. | PowerShell |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
JOIN profiles ON users.id = profiles.status | JOIN profiles ON users.id = profiles.status | Correct. | SQL |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
'data' + 50 | 'data' + 50.to_s | Convert int. | Ruby |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if foo = 68: | if foo == 68: | Use == for comparison. | Python |
#content {{ color: #333; }} | #content {{ color: #333; }} | Correct. | CSS |
<ul><li>test<li>test</ul> | <ul><li>test</li><li>test</li></ul> | Close li. | HTML |
if a = 74 | if a == 74 | Use ==. | Ruby |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
// comment | /* comment */ | Use /* */. | CSS |
if (val = 20) {{}} | if (val === 20) {{}} | Use === for equality. | JavaScript |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
def compute(val):
return val + 1 | def compute(val):
return val + 1 | Correct. | Python |
for result in range(87)
print(result) | for result in range(87):
print(result) | Colon after for. | Python |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
const c = 40; c = 59; | let c = 40; c = 59; | Cannot reassign const. | JavaScript |
let s = String::from("result"); let r=&s; s.push_str("!"); | let mut s = String::from("result"); let r=&s; println!("{{}}", r); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
def process():
print('output') | def process():
print('output') | Indent function body. | Python |
<entry name='hello'/> | <entry name="hello"/> | Double quotes. | XML |
int[] list = new int[15];
list[15] = 5; | int[] list = new int[15];
if (15 < list.length) list[15] = 5; | Check bounds. | Java |
if (val = 31) {{}} | if (val == 31) {{}} | Use ==. | Kotlin |
name: hello
age: 45 | name: hello
age: 45 | Correct. | YAML |
object Item {{ def main(args: Array[String]) = println("result") }} | object Item {{ def main(args: Array[String]): Unit = println("result") }} | Add return type Unit. | Scala |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
function foo(result)
print(result)
end | function foo(result)
print(result)
end | Correct. | Lua |
if foo = 59 | if foo == 59 | Use ==. | MATLAB |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
items[77] | if items.indices.contains(77) {{ items[77] }} | Check index. | Swift |
for (z in values) | for (z of values) | for...in iterates keys. | JavaScript |
function test(val:string){{return val;}} test(38); | function test(val:string){{return val;}} test('output'); | Pass correct type. | TypeScript |
const a; | const a = 68; | Initialize const. | JavaScript |
function handle() {{ echo 'test'; }} | function handle() {{ echo 'test'; }} | Correct. | PHP |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
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 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.