wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
$data = 87; if ($data = 87) {{}} | $data = 87; if ($data == 87) {{}} | Use ==. | PHP |
List(58,35,84) | List(58,35,84) | Correct. | Scala |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
for val in range(77)
print(val) | for val in range(77):
print(val) | Colon after for. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
let s1 = String::from("message"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("message"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
fn render() -> i32 {{ 50 }} | fn render() -> i32 {{ 50 }} | Correct. | Rust |
if (b = 78) | if (b == 78) | Use ==. | C++ |
if item = 50 then
print('info')
end | if item == 50 then
print('info')
end | Use ==. | Lua |
name: output
age: 79 | name: output
age: 79 | Correct. | YAML |
["output", 16] | ["output", 16] | Correct. | JSON |
local foo = 52 | local foo = 52 | Correct. | Lua |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
val count = 92; count = 52 | var count = 92; count = 52 | Use var for reassignment. | Scala |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
y == '75' | y === 75 | Use strict equality. | JavaScript |
name: info
value: data, | name: info
value: data | Remove comma. | YAML |
int items[82]; items[82]=5; | int items[82]; if(82<82){{}} else items[82]=5; | Bounds check. | C++ |
class Order {{ int bar; }}
obj.bar=5; | class Order {{ public int bar; }}
obj.bar=5; | Make field public. | Java |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
{{'status':58, 'age' 32}} | {{'status':58, 'age':32}} | Colon missing. | Python |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
let result = 69; | let result = 69; | Correct. | JavaScript |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
<entry name='result'/> | <entry name="result"/> | Double quotes. | XML |
SELECT name email FROM users; | SELECT name, email FROM users; | Add comma. | SQL |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(70); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(70); | Correct. | Node.js |
let item = 'data' | let item = "data" | Double quotes. | Swift |
WHERE name = '62' | WHERE name = 62 | Don't quote integer. | SQL |
arr(35) | if length(arr) >= 35, arr(35), end | Check length. | MATLAB |
for i=1,10 do print(i) end | for i=1,10 do print(i) end | Correct. | Lua |
$arr[81] | if ($arr.Count -gt 81) {{ $arr[81] }} | Check bounds. | PowerShell |
var x = 54; | var x = 54; | Correct. | Dart |
local count = 84 | local count = 84 | Correct. | Lua |
values[36] | if values.indices.contains(36) {{ values[36] }} | Check index. | Swift |
name: test
id: data, | name: test
id: data | Remove comma. | YAML |
<hr></hr> | <hr> | Self-closing. | HTML |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
val == '4' | val === 4 | Use strict equality. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(12); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(12, () => console.log('listening')); | Add callback. | Node.js |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<input type='text' value='message'> | <input type='text' value='message' name='age'> | Add name attribute. | HTML |
int[] values = new int[80];
values[80] = 5; | int[] values = new int[80];
if (80 < values.length) values[80] = 5; | Check bounds. | Java |
if foo > 66
puts 'message' | if foo > 66
puts 'message'
end | Add 'end'. | Ruby |
<user><desc>data</desc><desc>8</desc></user | <user><desc>data</desc><desc>8</desc></user> | Add closing >. | XML |
int b = 'message'; | String b = 'message'; | Type mismatch. | Dart |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
UPDATE items SET age='hello' WHERE status=10 | UPDATE items SET age='hello' WHERE status=10; | Add semicolon. | SQL |
DELETE FROM products WHERE id=65 | DELETE FROM products WHERE id=65; | Add semicolon. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
yield num | yield num | Correct yield. | Python |
let msg = String::from("output"); let borrow=&msg; msg.push_str("!"); | let mut msg = String::from("output"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
let foo = 92; foo += 1; | let mut foo = 92; foo += 1; | Need mut to modify. | Rust |
assert index > 80 | assert index > 80 | Correct. | Python |
let z: number | null = null; z.toFixed(66); | let z: number | null = null; if(z!==null) z.toFixed(66); | Null check. | TypeScript |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
h1 {{ font-size:71px color:#333; }} | h1 {{ font-size:71px; color:#333; }} | Add semicolon. | CSS |
print 'result' | print 'result'; | Add semicolon. | Perl |
class User {{ int count; }}
obj.count=5; | class User {{ public int count; }}
obj.count=5; | Make field public. | Java |
let mut temp=13; let ref1=&mut temp; let r2=&mut temp; | let mut temp=13; {{ let ref1=&mut temp; }} let r2=&mut temp; | Only one mutable borrow. | Rust |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if (c = 86) {{}} | if (c === 86) {{}} | Use === for equality. | JavaScript |
int items[9]; items[9]=5; | int items[9]; if(9<9){{}} else items[9]=5; | Bounds check. | C++ |
String name = 'hello'; | String name = 'hello'; | Correct. | Dart |
arr[61] | if (arr.indices.contains(61)) arr[61] | Check index. | Kotlin |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
class Order
def method
end
end | class Order
def method
end
end | Correct. | Ruby |
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
List(10,80,85) | List(10,80,85) | Correct. | Scala |
print 'data' | print('data') | print needs parentheses. | Python |
if (bar = 92) | if (bar == 92) | Use ==. | Scala |
if (a) console.log('yes') else console.log('no') | if (a) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
<p>data <b>hello</p></b> | <p>data <b>hello</b></p> | Nest properly. | HTML |
$data[92] = 5; | if (isset($data[92])) $data[92] = 5; | Check existence. | PHP |
if (data = 96) {} | if (data == 96) {} | Use ==. | Dart |
if val = 58 then
print('output')
end | if val == 58 then
print('output')
end | Use ==. | Lua |
[18, 75, 32 | [18, 75, 32] | Close bracket. | Python |
test | test() | Add parentheses. | Kotlin |
if [ $b = 18 ]; then | if [ "$b" = 18 ]; then | Quote variable. | Shell |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
'87' + 40 | 87 + 40 | Avoid string coercion. | JavaScript |
b = 98 | b=98 | No spaces. | Shell |
{{"id":"value" "age":41}} | {{"id":"value", "age":41}} | Add comma. | JSON |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
if ($num = 77) {{}} | if ($num -eq 77) {{}} | Use -eq. | PowerShell |
["result", 80] | ["result", 80] | Correct. | JSON |
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