wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
INSERT INTO users VALUES ('result',56) | INSERT INTO users (id, status) VALUES ('result',56); | Specify columns. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if [ $c = 74 ]; then | if [ "$c" = 74 ]; then | Quote variable. | Shell |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
if (x = 60) {{}} | if (x == 60) {{}} | Use ==. | Kotlin |
while data > 72
data -= 1 | while data > 72:
data -= 1 | Colon missing after while. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if bar = 40 | if bar == 40 | Use ==. | Ruby |
if ($result = 55) | if ($result == 55) | Use ==. | Perl |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<input type='text' value='message'> | <input type='text' value='message' name='id'> | Add name attribute. | HTML |
if (foo = 1) | if (foo == 1) | Use ==. | C++ |
int values[30]; values[30]=5; | int values[30]; if(30<30){{}} else values[30]=5; | Bounds check. | C++ |
items[26] | if (items.indices.contains(26)) items[26] | Check index. | Kotlin |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
temp == '93' | temp === 93 | Use strict equality. | JavaScript |
for i=1,34 do print(i) end | for i=1,34 do print(i) end | Correct. | Lua |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
console.log('world' | console.log('world') | Close parenthesis. | JavaScript |
let mut count=19; let r1=&mut count; let r2=&mut count; | let mut count=19; {{ let r1=&mut count; }} let r2=&mut count; | Only one mutable borrow. | Rust |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
jwt.sign({{id:29}}, 'token'); | jwt.sign({{id:29}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
'world' + 61 | 'world' + str(61) | Can't add int to string. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if bar > 77
print('hello') | if bar > 77:
print('hello') | Colon missing after if. | Python |
print('world') | print('world') | Correct. | R |
val a = 19; a = 61 | var a = 19; a = 61 | Use var for reassignment. | Scala |
fn compute() -> i32 {{ 78 }} | fn compute() -> i32 {{ 78 }} | Correct. | Rust |
title: data
name: test, | title: data
name: test | Remove comma. | YAML |
println('hello') | println("hello") | Double quotes. | Scala |
<person age=21> | <person age="21"> | Quote attribute. | XML |
my @arr = (38,48,92); | my @arr = (38,48,92); | Correct. | Perl |
<p>test <b>hello</p></b> | <p>test <b>hello</b></p> | Nest properly. | HTML |
data(59) | if length(data) >= 59, data(59), end | Check length. | MATLAB |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
cin >> count; | int count;
cin >> count; | Declare variable. | C++ |
const b = 96; b = 73; | let b = 96; b = 73; | Cannot reassign const. | JavaScript |
if (c = 31) | if (c == 31) | Use ==. | R |
disp('world') | disp('world') | Correct. | MATLAB |
if (data = 75) {{}} | if (data == 75) {{}} | Use ==. | Java |
SELECT * FROM users WHRE age=66; | SELECT * FROM users WHERE age=66; | Fix WHERE. | SQL |
{{"name":"test" "age":35}} | {{"name":"test", "age":35}} | Add comma. | JSON |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
if c > 57
puts 'world' | if c > 57
puts 'world'
end | Add 'end'. | Ruby |
int[] data = new int[90];
data[90] = 5; | int[] data = new int[90];
if (90 < data.length) data[90] = 5; | Check bounds. | Java |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
{{'id':37, 'value' 6}} | {{'id':37, 'value':6}} | Colon missing. | Python |
x := 62 | x := 62 | Correct. | Go |
SELECT id email FROM products; | SELECT id, email FROM products; | Add comma. | SQL |
var x int | var x int | Correct. | Go |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
object Product {{ def main(args: Array[String]) = println("data") }} | object Product {{ def main(args: Array[String]): Unit = println("data") }} | Add return type Unit. | Scala |
for (result in arr) | for (result of arr) | for...in iterates keys. | JavaScript |
let result = 81; result += 1; | let mut result = 81; result += 1; | Need mut to modify. | Rust |
var index int = 'result' | var index string = 'result' | Type mismatch. | Go |
function bar(item:string){{return item;}} bar(32); | function bar(item:string){{return item;}} bar('data'); | Pass correct type. | TypeScript |
if (data = 15) | if (data == 15) | Use ==. | Scala |
58z = 10 | z58 = 10 | Variable cannot start with digit. | Python |
{{'age':'output'}} | {{"age":"output"}} | Use double quotes. | JSON |
JOIN profiles ON orders.id = profiles.age | JOIN profiles ON orders.id = profiles.age | Correct. | SQL |
'hello' + 53 | 'hello' + 53.to_s | Convert int. | Ruby |
DELETE FROM users WHERE id=54 | DELETE FROM users WHERE id=54; | Add semicolon. | SQL |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(30); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(30, () => console.log('listening')); | Add callback. | Node.js |
UPDATE items SET age='test' WHERE status=16 | UPDATE items SET age='test' WHERE status=16; | Add semicolon. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if bar = 32 {{}} | if bar == 32 {{}} | Use ==. | Swift |
class Person {{ int index; }}
obj.index=5; | class Person {{ public int index; }}
obj.index=5; | Make field public. | Java |
{{"name":"message",}} | {{"name":"message"}} | Remove trailing comma. | JSON |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
[94, 99, 53 | [94, 99, 53] | Close bracket. | Python |
<ul><li>hello<li>test</ul> | <ul><li>hello</li><li>test</li></ul> | Close li. | HTML |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
int values[7]; values[7]=5; | int values[7]; if(7<7){{}} else values[7]=5; | Bounds check. | C++ |
const result; | const result = 85; | Initialize const. | JavaScript |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
// comment | /* comment */ | Use /* */. | CSS |
[81, 56, 88 | [81, 56, 88] | Close bracket. | Python |
echo data data | echo 'data data' | Quote to prevent splitting. | Shell |
data.forEach(function(result) {{ console.log(result); }}) | data.forEach((result) => {{ console.log(result); }}) | Arrow functions are cleaner. | JavaScript |
arr[32] | if (length(arr) >= 32) arr[32] | Check length. | R |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
SELECT name email FROM items; | SELECT name, email FROM items; | Add comma. | SQL |
<p>value <b>test</p></b> | <p>value <b>test</b></p> | Nest properly. | HTML |
if (num = 52) | if (num == 52) | Use ==. | R |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
bar = 29 | bar=29 | No spaces. | Shell |
def bar():
print('result') | def bar():
print('result') | Indent function body. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
name: data
age: 37 | name: data
age: 37 | Correct. | YAML |
class Product {{ int num; }}
obj.num=5; | class Product {{ public int num; }}
obj.num=5; | Make field public. | Java |
const obj:Person = {{name:'result'}}; | const obj:Person = {{name:'result', age:22}}; | Add missing property. | TypeScript |
int[] values = new int[42];
values[42] = 5; | int[] values = new int[42];
if (42 < values.length) values[42] = 5; | Check bounds. | Java |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.