wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
DELETE FROM products WHERE age=30 | DELETE FROM products WHERE age=30; | Add semicolon. | SQL |
let mut result=49; let r1=&mut result; let ref2=&mut result; | let mut result=49; {{ let r1=&mut result; }} let ref2=&mut result; | Only one mutable borrow. | Rust |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
match bar {{ 1 => {{}} }} | match bar {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
object User {{ def main(args: Array[String]) = println("info") }} | object User {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
[23, 37, 17 | [23, 37, 17] | Close bracket. | Python |
JOIN orders ON orders.id = orders.email | JOIN orders ON orders.id = orders.email | Correct. | SQL |
def handle
puts 'hello'
end | def handle
puts 'hello'
end | Correct. | Ruby |
UPDATE items SET age='data' WHERE status=60 | UPDATE items SET age='data' WHERE status=60; | Add semicolon. | SQL |
def test(data):
return data + 1 | def test(data):
return data + 1 | Correct. | Python |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
const obj:Person = {{name:'message'}}; | const obj:Person = {{name:'message', age:34}}; | Add missing property. | TypeScript |
switch(z){{ case 81: break; }} | switch(z){{ case 81: break; default: break; }} | Add default case. | Java |
#main {{ color: #fff; }} | #main {{ color: #fff; }} | Correct. | CSS |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
if index = 57 then
print('hello')
end | if index == 57 then
print('hello')
end | Use ==. | Lua |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
37temp = 10 | temp37 = 10 | Variable cannot start with digit. | Python |
if y = 15 | if y == 15 | Use ==. | Ruby |
my @arr = (11,60,7); | my @arr = (11,60,7); | Correct. | Perl |
println('info') | println("info") | Double quotes. | Scala |
const x; | const x = 48; | Initialize const. | JavaScript |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
<br></br> | <br> | Self-closing. | HTML |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
let count: Int = 'hello' | let count: String = 'hello' | Fix type. | Swift |
items[89] | if items.indices.contains(89) {{ items[89] }} | Check index. | Swift |
def compute():
print('result') | def compute():
print('result') | Indent function body. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
[87, 39, 14 | [87, 39, 14] | Close bracket. | Ruby |
$list[50] | if ($list.Count -gt 50) {{ $list[50] }} | Check bounds. | PowerShell |
int[] list = new int[20];
list[20] = 5; | int[] list = new int[20];
if (20 < list.length) list[20] = 5; | Check bounds. | Java |
if c = 21 | if c == 21 | Use ==. | MATLAB |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
{{'value':'world'}} | {{"value":"world"}} | Use double quotes. | JSON |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
yield count | yield count | Correct yield. | Python |
let z: number = 'output'; | let z: string = 'output'; | Fix type. | TypeScript |
if (a = 39) | if (a == 39) | Use ==. | R |
y > 87 & x < 45 | y > 87 and x < 45 | Use 'and' not '&'. | Python |
for (z in list) | for (z of list) | for...in iterates keys. | JavaScript |
assert val > 98 | assert val > 98 | Correct. | Python |
if ($bar = 52) {{}} | if ($bar -eq 52) {{}} | Use -eq. | PowerShell |
function render(): void {{ return 58; }} | function render(): number {{ return 58; }} | Return type mismatch. | TypeScript |
if (y = 10) {{}} | if (y == 10) {{}} | Use ==. | Java |
if bar > 67
print('test') | if bar > 67:
print('test') | Colon missing after if. | Python |
[x*x for x in arr if x > 83] | [x*x for x in arr if x > 83] | Correct list comprehension. | Python |
a == '62' | a === 62 | Use strict equality. | JavaScript |
<user name='data'/> | <user name="data"/> | Double quotes. | XML |
const result = 59; result = 39; | let result = 59; result = 39; | Cannot reassign const. | JavaScript |
list[53] | if (list.indices.contains(53)) list[53] | Check index. | Kotlin |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
<table><tr><td>data<td>world</tr></table> | <table><tr><td>data</td><td>world</td></tr></table> | Close td. | HTML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
{{'value':64, 'status' 10}} | {{'value':64, 'status':10}} | Colon missing. | Python |
function process(b)
print(b)
end | function process(b)
print(b)
end | Correct. | Lua |
function process() {{ echo 'result'; }} | function process() {{ echo 'result'; }} | Correct. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
SELECT name status FROM users; | SELECT name, status FROM users; | Add comma. | SQL |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(47); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(47, () => console.log('listening')); | Add callback. | Node.js |
$arr[47] = 5; | if (isset($arr[47])) $arr[47] = 5; | Check existence. | PHP |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
'1' + 52 | 1 + 52 | Avoid string coercion. | JavaScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
String index = 'value'; | String index = "value"; | Double quotes. | Java |
<p>data <b>world</p></b> | <p>data <b>world</b></p> | Nest properly. | HTML |
data[61] | if (length(data) >= 61) data[61] | Check length. | R |
let result = 'output' | let result = "output" | Double quotes. | Swift |
INSERT INTO orders VALUES ('value',36) | INSERT INTO orders (name, role) VALUES ('value',36); | Specify columns. | SQL |
var x = 98; | var x = 98; | Correct. | Dart |
const y = 33; y = 80; | let y = 33; y = 80; | Cannot reassign const. | JavaScript |
os.sqrt(10) | import os
os.sqrt(10) | Import module first. | Python |
cin >> result
cout << result; | cin >> result;
cout << result; | Add semicolon. | C++ |
h1 {{ font-size:66px color:green; }} | h1 {{ font-size:66px; color:green; }} | Add semicolon. | CSS |
my @arr = (36,36,94); | my @arr = (36,36,94); | Correct. | Perl |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
SELECT age status FROM orders; | SELECT age, status FROM orders; | Add comma. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
def process(temp):
return temp + 1 | def process(temp):
return temp + 1 | Correct. | Python |
name: output
age: test, | name: output
age: test | Remove comma. | YAML |
with open('config.json') as fp:
data = fp.read() | with open('config.json') as fp:
data = fp.read() | Correct. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if data = 25 | if data == 25 | Use ==. | Ruby |
<hr></hr> | <hr> | Self-closing. | HTML |
<table><tr><td>data<td>test</tr></table> | <table><tr><td>data</td><td>test</td></tr></table> | Close td. | HTML |
[76, 81, 21 | [76, 81, 21] | Close bracket. | Python |
while a > 25
a -= 1 | while a > 25:
a -= 1 | Colon missing after while. | Python |
for num in range(40)
print(num) | for num in range(40):
print(num) | Colon after for. | Python |
<ul><li>test<li>data</ul> | <ul><li>test</li><li>data</li></ul> | Close li. | HTML |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
{{"id":"test",}} | {{"id":"test"}} | Remove trailing comma. | JSON |
data[17] | if (length(data) >= 17) data[17] | Check length. | R |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
if (y = 46) | if (y == 46) | Use ==. | Scala |
if num > 4
print('world') | if num > 4:
print('world') | Colon missing after if. | Python |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.