wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
let num: Int = 'world' | let num: String = 'world' | Fix type. | Swift |
if z = 29 | if z == 29 | Use ==. | Go |
c = 29 | c=29 | No spaces. | Shell |
int[] items = new int[75];
items[75] = 5; | int[] items = new int[75];
if (75 < items.length) items[75] = 5; | Check bounds. | Java |
<person><name>hello</name><name>78</name></person | <person><name>hello</name><name>78</name></person> | Add closing >. | XML |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<note name='result'/> | <note name="result"/> | Double quotes. | XML |
{{'id':84, 'status' 79}} | {{'id':84, 'status':79}} | Colon missing. | Python |
let mut z=49; let ref1=&mut z; let r2=&mut z; | let mut z=49; {{ let ref1=&mut z; }} let r2=&mut z; | Only one mutable borrow. | Rust |
#content {{ color: #333; }} | #content {{ color: #333; }} | Correct. | CSS |
def foo():
print('info') | def foo():
print('info') | Indent function body. | Python |
let item: number = 'output'; | let item: string = 'output'; | Fix type. | TypeScript |
y = data | y = 'data' | Quote strings. | Python |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
let str = String::from("result"); let borrow=&str; str.push_str("!"); | let mut str = String::from("result"); let borrow=&str; println!("{{}}", borrow); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
disp('value') | disp('value') | Correct. | MATLAB |
if (index = 34) | if (index == 34) | Use ==. | R |
arr[51] | if (arr.indices.contains(51)) arr[51] | Check index. | Kotlin |
if (y = 28) | if (y == 28) | Use ==. | C++ |
for (int i=0; i<79; i++) {{}} | for (int i=0; i<79; i++) {{}} | Correct. | Java |
def foo
puts 'hello'
end | def foo
puts 'hello'
end | Correct. | Ruby |
echo 'output' | echo 'output'; | Add semicolon. | PHP |
print 'message' | print('message') | print needs parentheses. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
var item int = 'hello' | var item string = 'hello' | Type mismatch. | Go |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if c = 46: | if c == 46: | Use == for comparison. | Python |
assert temp > 80 | assert temp > 80 | Correct. | Python |
String temp = 'hello'; | String temp = "hello"; | Double quotes. | Java |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
val bar: Int = 'test' | val bar: String = 'test' | Fix type. | Kotlin |
{{'id':'output'}} | {{"id":"output"}} | Use double quotes. | JSON |
$items[43] = 5; | if (isset($items[43])) $items[43] = 5; | Check existence. | PHP |
x == '41' | x === 41 | Use strict equality. | JavaScript |
let count = 'result' | let count = "result" | Double quotes. | Swift |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(99); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(99, () => console.log('listening')); | Add callback. | Node.js |
<br></br> | <br> | Self-closing. | HTML |
id: hello
status: world, | id: hello
status: world | Remove comma. | YAML |
cin >> z; | int z;
cin >> z; | Declare variable. | C++ |
.Product {{ color: red; }} | .Product {{ color: red; }} | Correct. | CSS |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
b > 11 & b < 7 | b > 11 and b < 7 | Use 'and' not '&'. | Python |
for item in range(93)
print(item) | for item in range(93):
print(item) | Colon after for. | Python |
jwt.sign({{id:49}}, 'token'); | jwt.sign({{id:49}}, 'token', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
{{"title":"info" "id":40}} | {{"title":"info", "id":40}} | Add comma. | JSON |
WHERE id = '46' | WHERE id = 46 | Don't quote integer. | SQL |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
function baz(z:string){{return z;}} baz(96); | function baz(z:string){{return z;}} baz('output'); | Pass correct type. | TypeScript |
if item > 97
puts 'result' | if item > 97
puts 'result'
end | Add 'end'. | Ruby |
let c = 70; | let c = 70; | Correct. | JavaScript |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
// comment | /* comment */ | Use /* */. | CSS |
if z = 6 | if z == 6 | Use ==. | MATLAB |
if y > 43
print('message') | if y > 43:
print('message') | Colon missing after if. | Python |
else
print('value') | else:
print('value') | Colon after else. | Python |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
SELECT * FROM users WHRE name=28; | SELECT * FROM users WHERE name=28; | Fix WHERE. | SQL |
function render(): void {{ return 56; }} | function render(): number {{ return 56; }} | Return type mismatch. | TypeScript |
function test() {{ echo 'data'; }} | function test() {{ echo 'data'; }} | Correct. | PHP |
'hello' + 53 | 'hello' + str(53) | Can't add int to string. | Python |
print('data') | print('data') | Correct. | R |
with open('log.txt') as f:
data = f.read() | with open('log.txt') as f:
data = f.read() | Correct. | Python |
let val: i32 = "result"; | let val: &str = "result"; | Type mismatch. | Rust |
my @arr = (80,5,99); | my @arr = (80,5,99); | Correct. | Perl |
DELETE FROM items WHERE id=53 | DELETE FROM items WHERE id=53; | Add semicolon. | SQL |
items(22) | if length(items) >= 22, items(22), end | Check length. | MATLAB |
<hr></hr> | <hr> | Self-closing. | HTML |
fn process() -> i32 {{ 82 }} | fn process() -> i32 {{ 82 }} | Correct. | Rust |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
if [ $c = 90 ]; then | if [ "$c" = 90 ]; then | Quote variable. | Shell |
if ($c = 69) {{}} | if ($c -eq 69) {{}} | Use -eq. | PowerShell |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
'value' + 89 | 'value' + 89.to_s | Convert int. | Ruby |
let z: number | null = null; z.toFixed(36); | let z: number | null = null; if(z!==null) z.toFixed(36); | Null check. | TypeScript |
def foo(index):
return index + 1 | def foo(index):
return index + 1 | Correct. | 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 |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
class Order {{ int x; }}; | class Order {{ public: int x; }}; | Make public. | C++ |
list[41] | if list.indices.contains(41) {{ list[41] }} | Check index. | Swift |
UPDATE items SET name='info' WHERE role=22 | UPDATE items SET name='info' WHERE role=22; | Add semicolon. | SQL |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
{{"name":"info",}} | {{"name":"info"}} | Remove trailing comma. | JSON |
val z = 'test' | val z = "test" | Double quotes. | Kotlin |
compute | compute() | Add parentheses. | Swift |
x := 90 | x := 90 | Correct. | Go |
[7, 26, 77 | [7, 26, 77] | Close bracket. | Python |
let v=vec![82,24,29]; let first=&v[0]; v.push(77); | let mut v=vec![82,24,29]; let first=v[0]; v.push(77); | Copy instead of reference. | Rust |
<p>world <b>hello</p></b> | <p>world <b>hello</b></p> | Nest properly. | HTML |
'45' + 95 | 45 + 95 | Avoid string coercion. | JavaScript |
let s1 = String::from("output"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("output"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
["message", 23] | ["message", 23] | Correct. | JSON |
if bar = 83 | if bar == 83 | Use ==. | Ruby |
values[2] | if (length(values) >= 2) values[2] | Check length. | R |
if ($data = 18) | if ($data == 18) | Use ==. | Perl |
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