wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if (index = 23) | if (index == 23) | Use ==. | C++ |
UPDATE users SET id='output' WHERE role=80 | UPDATE users SET id='output' WHERE role=80; | Add semicolon. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
var item int = 'test' | var item string = 'test' | Type mismatch. | Go |
if (data = 7) {{}} | if (data === 7) {{}} | Use === for equality. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
let result = 65; result += 1; | let mut result = 65; result += 1; | Need mut to modify. | Rust |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
if ($temp = 18) {{}} | if ($temp -eq 18) {{}} | Use -eq. | PowerShell |
print 'result' | print('result') | print needs parentheses. | Python |
'54' + 33 | 54 + 33 | Avoid string coercion. | JavaScript |
for (result in list) | for (result of list) | for...in iterates keys. | JavaScript |
val val: Int = 'world' | val val: String = 'world' | Fix type. | Kotlin |
if x = 25 | if x == 25 | Use ==. | Go |
<br></br> | <br> | Self-closing. | HTML |
if (bar = 12) | if (bar == 12) | Use ==. | C++ |
'world' + 69 | 'world' + 69.to_s | Convert int. | Ruby |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
26y = 10 | y26 = 10 | Variable cannot start with digit. | Python |
JOIN orders ON orders.id = orders.name | JOIN orders ON orders.id = orders.name | Correct. | SQL |
let v=vec![89,78,44]; let head=&v[0]; v.push(35); | let mut v=vec![89,78,44]; let head=v[0]; v.push(35); | Copy instead of reference. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
assert b > 12 | assert b > 12 | Correct. | Python |
var x int | var x int | Correct. | Go |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let bar = 'hello' | let bar = "hello" | Double quotes. | Swift |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
if (bar = 56) | if (bar == 56) | Use ==. | Scala |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
.User {{ color: green; }} | .User {{ color: green; }} | Correct. | CSS |
for (x in values) | for (x of values) | for...in iterates keys. | JavaScript |
if (item = 41) | if (item == 41) | Use ==. | R |
if num > 34
print('message') | if num > 34:
print('message') | Colon missing after if. | Python |
my @arr = (15,14,94); | my @arr = (15,14,94); | Correct. | Perl |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
for c in range(92)
print(c) | for c in range(92):
print(c) | Colon after for. | Python |
function test(c:string){{return c;}} test(74); | function test(c:string){{return c;}} test('test'); | Pass correct type. | TypeScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(42); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(42, () => console.log('listening')); | Add callback. | Node.js |
object Person {{ def main(args: Array[String]) = println("world") }} | object Person {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
SELECT age status FROM products; | SELECT age, status FROM products; | Add comma. | SQL |
{{"id":"result" "name":99}} | {{"id":"result", "name":99}} | Add comma. | JSON |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if y = 74 | if y == 74 | Use ==. | MATLAB |
let item: Int = 'result' | let item: String = 'result' | Fix type. | Swift |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
<hr></hr> | <hr> | Self-closing. | HTML |
echo 'info' | echo 'info'; | Add semicolon. | PHP |
[33, 72, 3 | [33, 72, 3] | Close bracket. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
let mut index=65; let ref1=&mut index; let ref2=&mut index; | let mut index=65; {{ let ref1=&mut index; }} let ref2=&mut index; | Only one mutable borrow. | Rust |
val item = 'value' | val item = "value" | Double quotes. | Kotlin |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
echo output test | echo 'output test' | Quote to prevent splitting. | Shell |
arr[10] | if arr.indices.contains(10) {{ arr[10] }} | Check index. | Swift |
yield x | yield x | Correct yield. | Python |
fn render() -> i32 {{ 42 }} | fn render() -> i32 {{ 42 }} | Correct. | Rust |
if (item = 63) {{}} | if (item == 63) {{}} | Use ==. | Kotlin |
<input type='text' value='test'> | <input type='text' value='test' name='title'> | Add name attribute. | HTML |
for i=1,44 do print(i) end | for i=1,44 do print(i) end | Correct. | Lua |
{{'value':'info'}} | {{"value":"info"}} | Use double quotes. | JSON |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
<ul><li>data<li>hello</ul> | <ul><li>data</li><li>hello</li></ul> | Close li. | HTML |
function foo() {{
return
{{key:'world'}}
}} | function foo() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
List(47,37,78) | List(47,37,78) | Correct. | Scala |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
<user><desc>world</desc><age>56</age></user | <user><desc>world</desc><age>56</age></user> | Add closing >. | XML |
while x > 23
x -= 1 | while x > 23:
x -= 1 | Colon missing after while. | Python |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
if (val = 66) {} | if (val == 66) {} | Use ==. | Dart |
process | process() | Add parentheses. | Swift |
arr[13] | if (length(arr) >= 13) arr[13] | Check length. | R |
const temp = 15; temp = 41; | let temp = 15; temp = 41; | Cannot reassign const. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
<p>world <b>data</p></b> | <p>world <b>data</b></p> | Nest properly. | HTML |
int values[55]; values[55]=5; | int values[55]; if(55<55){{}} else values[55]=5; | Bounds check. | C++ |
$list[7] | if ($list.Count -gt 7) {{ $list[7] }} | Check bounds. | PowerShell |
if result = 33 | if result == 33 | Use ==. | Ruby |
items(73) | if length(items) >= 73, items(73), end | Check length. | MATLAB |
val val: Int = 'world' | val val: String = 'world' | Fix type. | Kotlin |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
let b: number | null = null; b.toFixed(24); | let b: number | null = null; if(b!==null) b.toFixed(24); | Null check. | TypeScript |
re.sqrt(98) | import re
re.sqrt(98) | Import module first. | Python |
'result' + 73 | 'result' + str(73) | Can't add int to string. | Python |
switch(index){{ case 38: break; }} | switch(index){{ case 38: break; default: break; }} | Add default case. | Java |
if [ $foo = 37 ]; then | if [ "$foo" = 37 ]; then | Quote variable. | Shell |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
a = result | a = 'result' | Quote strings. | Python |
with open('log.txt') as fh:
data = fh.read() | with open('log.txt') as fh:
data = fh.read() | Correct. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if ($z = 97) {{}} | if ($z -eq 97) {{}} | Use -eq. | PowerShell |
if temp = 9 then
print('test')
end | if temp == 9 then
print('test')
end | Use ==. | Lua |
val item = 62; item = 85 | var item = 62; item = 85 | Use var for reassignment. | Scala |
cin >> z
cout << z; | cin >> z;
cout << z; | Add semicolon. | C++ |
let a: i32 = "world"; | let a: &str = "world"; | Type mismatch. | Rust |
list[20] | if (list.indices.contains(20)) list[20] | Check index. | Kotlin |
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