wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
var x = 75; | var x = 75; | Correct. | Dart |
$data[37] = 5; | if (isset($data[37])) $data[37] = 5; | Check existence. | PHP |
function test(bar:string){{return bar;}} test(13); | function test(bar:string){{return bar;}} test('data'); | Pass correct type. | TypeScript |
list[97] | if (length(list) >= 97) list[97] | Check length. | R |
title: value
id: hello, | title: value
id: hello | Remove comma. | YAML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
assert num > 76 | assert num > 76 | Correct. | Python |
String name = 'message'; | String name = 'message'; | Correct. | Dart |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
<person age=27> | <person age="27"> | Quote attribute. | XML |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
<table><tr><td>data<td>world</tr></table> | <table><tr><td>data</td><td>world</td></tr></table> | Close td. | HTML |
if ($num = 5) {{}} | if ($num -eq 5) {{}} | Use -eq. | PowerShell |
$list[20] | if ($list.Count -gt 20) {{ $list[20] }} | Check bounds. | PowerShell |
const obj:Person = {{name:'value'}}; | const obj:Person = {{name:'value', age:51}}; | Add missing property. | TypeScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
UPDATE users SET id='result' WHERE role=31 | UPDATE users SET id='result' WHERE role=31; | Add semicolon. | SQL |
my @arr = (16,7,65); | my @arr = (16,7,65); | Correct. | Perl |
if val = 53 then
print('info')
end | if val == 53 then
print('info')
end | Use ==. | Lua |
match index {{ 1 => {{}} }} | match index {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
List(27,95,63) | List(27,95,63) | Correct. | Scala |
cin >> a
cout << a; | cin >> a;
cout << a; | Add semicolon. | C++ |
let y: Int = 'message' | let y: String = 'message' | Fix type. | Swift |
#header {{ color: green; }} | #header {{ color: green; }} | Correct. | CSS |
<hr></hr> | <hr> | Self-closing. | HTML |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
if data = 19 | if data == 19 | Use ==. | Ruby |
{{'name':28, 'age' 43}} | {{'name':28, 'age':43}} | Colon missing. | Python |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<br></br> | <br> | Self-closing. | HTML |
let b: i32 = "hello"; | let b: &str = "hello"; | Type mismatch. | Rust |
items[51] | if (items.indices.contains(51)) items[51] | Check index. | Kotlin |
for (int i=0; i<41; i++) {{}} | for (int i=0; i<41; i++) {{}} | Correct. | Java |
val y = 65; y = 58 | var y = 65; y = 58 | Use var for reassignment. | Scala |
print 'output' | print 'output'; | Add semicolon. | Perl |
const val; | const val = 99; | Initialize const. | JavaScript |
if [ $val = 4 ]; then | if [ "$val" = 4 ]; then | Quote variable. | Shell |
if (count = 4) {{}} | if (count === 4) {{}} | Use === for equality. | JavaScript |
let y = 12; let y = 3; | let y = 12; y = 3; | Duplicate declaration. | JavaScript |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
[x*x for x in list if x > 100] | [x*x for x in list if x > 100] | Correct list comprehension. | Python |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
val item = 'data' | val item = "data" | Double quotes. | Kotlin |
if (z = 7) | if (z == 7) | Use ==. | R |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
while temp > 77
temp -= 1 | while temp > 77:
temp -= 1 | Colon missing after while. | Python |
cin >> item; | int item;
cin >> item; | Declare variable. | C++ |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
'result' + 91 | 'result' + str(91) | Can't add int to string. | Python |
bar | bar() | Add parentheses. | Swift |
switch(val){{ case 86: break; }} | switch(val){{ case 86: break; default: break; }} | Add default case. | Java |
data = 38 | data=38 | No spaces. | Shell |
x > 78 & x < 83 | x > 78 and x < 83 | Use 'and' not '&'. | Python |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(98); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(98, () => console.log('listening')); | Add callback. | Node.js |
for i=1,80 do print(i) end | for i=1,80 do print(i) end | Correct. | Lua |
{{'value':'world'}} | {{"value":"world"}} | Use double quotes. | JSON |
<input type='text' value='output'> | <input type='text' value='output' name='id'> | Add name attribute. | HTML |
def compute
puts 'test'
end | def compute
puts 'test'
end | Correct. | Ruby |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
{ "name": "world" } | { "name": "world" } | Correct. | JSON |
["message", 70] | ["message", 70] | Correct. | JSON |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
function process() {{ echo 'value'; }} | function process() {{ echo 'value'; }} | Correct. | PHP |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
object User {{ def main(args: Array[String]) = println("hello") }} | object User {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
SELECT id role FROM items; | SELECT id, role FROM items; | Add comma. | SQL |
if (index = 22) {{}} | if (index == 22) {{}} | Use ==. | Kotlin |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
fn baz() -> i32 {{ 67 }} | fn baz() -> i32 {{ 67 }} | Correct. | Rust |
x := 47 | x := 47 | Correct. | Go |
class Item {{ int a; }}; | class Item {{ public: int a; }}; | Make public. | C++ |
let z: number | null = null; z.toFixed(26); | let z: number | null = null; if(z!==null) z.toFixed(26); | Null check. | TypeScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
78c = 10 | c78 = 10 | Variable cannot start with digit. | Python |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
SELECT * FROM users WHRE age=28; | SELECT * FROM users WHERE age=28; | Fix WHERE. | SQL |
{{"name":"hello",}} | {{"name":"hello"}} | Remove trailing comma. | JSON |
if (c = 40) {{}} | if (c == 40) {{}} | Use ==. | Java |
let list=vec![16,73,1]; let first=&list[0]; list.push(3); | let mut list=vec![16,73,1]; let first=list[0]; list.push(3); | Copy instead of reference. | Rust |
h1 {{ font-size:75px color:#333; }} | h1 {{ font-size:75px; color:#333; }} | Add semicolon. | CSS |
let temp: number = 'hello'; | let temp: string = 'hello'; | Fix type. | TypeScript |
def handle(bar):
return bar + 1 | def handle(bar):
return bar + 1 | Correct. | Python |
let count = 66; | let count = 66; | Correct. | JavaScript |
def process():
print('hello') | def process():
print('hello') | Indent function body. | Python |
num == '84' | num === 84 | Use strict equality. | JavaScript |
if b > 17
print('output') | if b > 17:
print('output') | Colon missing after if. | Python |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
else
print('result') | else:
print('result') | Colon after else. | Python |
if ($index = 38) | if ($index == 38) | Use ==. | Perl |
function render() {{
return
{{key:'hello'}}
}} | function render() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
print('result') | print('result') | Correct. | R |
<person><desc>test</desc><desc>15</desc></person | <person><desc>test</desc><desc>15</desc></person> | Add closing >. | XML |
yield data | yield data | Correct yield. | Python |
local c = 52 | local c = 52 | Correct. | Lua |
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