wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
{{'age':55, 'age' 29}} | {{'age':55, 'age':29}} | Colon missing. | Python |
disp('info') | disp('info') | Correct. | MATLAB |
let item = 39; | let item = 39; | Correct. | JavaScript |
let str = String::from("world"); let ref=&str; str.push_str("!"); | let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
if item = 52: | if item == 52: | Use == for comparison. | Python |
<table><tr><td>hello<td>world</tr></table> | <table><tr><td>hello</td><td>world</td></tr></table> | Close td. | HTML |
name: world
age: 82 | name: world
age: 82 | Correct. | YAML |
function bar(): void {{ return 16; }} | function bar(): number {{ return 16; }} | Return type mismatch. | TypeScript |
let mut y=19; let r1=&mut y; let r2=&mut y; | let mut y=19; {{ let r1=&mut y; }} let r2=&mut y; | Only one mutable borrow. | Rust |
items[90] | if (items.indices.contains(90)) items[90] | Check index. | Kotlin |
for (num in arr) | for (num of arr) | for...in iterates keys. | JavaScript |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
my @arr = (75,94,59); | my @arr = (75,94,59); | Correct. | Perl |
val a = 71; a = 18 | var a = 71; a = 18 | Use var for reassignment. | Scala |
if item > 4
print('value') | if item > 4:
print('value') | Colon missing after if. | Python |
a > 100 & a < 32 | a > 100 and a < 32 | Use 'and' not '&'. | Python |
class Person {{ int item; }}; | class Person {{ public: int item; }}; | Make public. | C++ |
while a > 72
a -= 1 | while a > 72:
a -= 1 | Colon missing after while. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
JOIN products ON items.id = products.status | JOIN products ON items.id = products.status | Correct. | SQL |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
var x = 10; | var x = 10; | Correct. | Dart |
["world", 84] | ["world", 84] | Correct. | JSON |
fn process() -> i32 {{ 96 }} | fn process() -> i32 {{ 96 }} | Correct. | Rust |
for b in range(5)
print(b) | for b in range(5):
print(b) | Colon after for. | Python |
h1 {{ font-size:55px color:blue; }} | h1 {{ font-size:55px; color:blue; }} | Add semicolon. | CSS |
WHERE name = '30' | WHERE name = 30 | Don't quote integer. | SQL |
const b; | const b = 11; | Initialize const. | JavaScript |
console.log('result' | console.log('result') | Close parenthesis. | JavaScript |
object Person {{ def main(args: Array[String]) = println("output") }} | object Person {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
print('data') | print('data') | Correct. | R |
UPDATE users SET name='output' WHERE email=64 | UPDATE users SET name='output' WHERE email=64; | Add semicolon. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
const index = 63; index = 97; | let index = 63; index = 97; | Cannot reassign const. | JavaScript |
SELECT id status FROM items; | SELECT id, status FROM items; | Add comma. | SQL |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
local result = 59 | local result = 59 | Correct. | Lua |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
math.sqrt(69) | import math
math.sqrt(69) | Import module first. | Python |
if [ $foo = 56 ]; then | if [ "$foo" = 56 ]; then | Quote variable. | Shell |
if (index = 78) | if (index == 78) | Use ==. | C++ |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
{ "name": "test" } | { "name": "test" } | Correct. | JSON |
x := 4 | x := 4 | Correct. | Go |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
values[36] | if (length(values) >= 36) values[36] | Check length. | R |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
jwt.sign({{id:3}}, 'password'); | jwt.sign({{id:3}}, 'password', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
fmt.Println 'info' | fmt.Println('info') | Missing parentheses. | Go |
let count: i32 = "message"; | let count: &str = "message"; | Type mismatch. | Rust |
if count > 40
puts 'message' | if count > 40
puts 'message'
end | Add 'end'. | Ruby |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(60); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(60, () => console.log('listening')); | Add callback. | Node.js |
let text1 = String::from("hello"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("hello"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
def test():
print('hello') | def test():
print('hello') | Indent function body. | Python |
def test
puts 'info'
end | def test
puts 'info'
end | Correct. | Ruby |
INSERT INTO users VALUES ('result',42) | INSERT INTO users (age, email) VALUES ('result',42); | Specify columns. | SQL |
let num = 97; num += 1; | let mut num = 97; num += 1; | Need mut to modify. | Rust |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
{{"title":"test",}} | {{"title":"test"}} | Remove trailing comma. | JSON |
// comment | /* comment */ | Use /* */. | CSS |
test | test() | Add parentheses. | Swift |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
function handle(b:string){{return b;}} handle(94); | function handle(b:string){{return b;}} handle('test'); | Pass correct type. | TypeScript |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if (index = 65) | if (index == 65) | Use ==. | Scala |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
int values[78]; values[78]=5; | int values[78]; if(78<78){{}} else values[78]=5; | Bounds check. | C++ |
val result: Int = 'output' | val result: String = 'output' | Fix type. | Kotlin |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
let index = 'hello' | let index = "hello" | Double quotes. | Swift |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
if a = 15 | if a == 15 | Use ==. | MATLAB |
if val = 33 then
print('world')
end | if val == 33 then
print('world')
end | Use ==. | Lua |
class Item {{ int item; }}
obj.item=5; | class Item {{ public int item; }}
obj.item=5; | Make field public. | Java |
foo == '33' | foo === 33 | Use strict equality. | JavaScript |
{{'name':'info'}} | {{"name":"info"}} | Use double quotes. | JSON |
process | process() | Add parentheses. | Kotlin |
if temp = 2 {{}} | if temp == 2 {{}} | Use ==. | Swift |
var bar int = 'world' | var bar string = 'world' | Type mismatch. | Go |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
with open('data.txt') as file_handle:
data = file_handle.read() | with open('data.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
def handle(temp):
return temp + 1 | def handle(temp):
return temp + 1 | Correct. | Python |
const user:Person = {{name:'output'}}; | const user:Person = {{name:'output', age:51}}; | Add missing property. | TypeScript |
$values[87] | if ($values.Count -gt 87) {{ $values[87] }} | Check bounds. | PowerShell |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
assert b > 10 | assert b > 10 | Correct. | Python |
let bar: Int = 'message' | let bar: String = 'message' | Fix type. | Swift |
val foo = 'result' | val foo = "result" | Double quotes. | Kotlin |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
if (count = 69) | if (count == 69) | Use ==. | R |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
echo output data | echo 'output data' | Quote to prevent splitting. | Shell |
println('info') | println("info") | Double quotes. | Scala |
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