wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
print 'hello' | print('hello') | print needs parentheses. | Python |
int arr[14]; arr[14]=5; | int arr[14]; if(14<14){{}} else arr[14]=5; | Bounds check. | C++ |
process | process() | Add parentheses. | Swift |
String z = 'info'; | String z = "info"; | Double quotes. | Java |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
var result int = 'message' | var result string = 'message' | Type mismatch. | Go |
<br></br> | <br> | Self-closing. | HTML |
render | render() | Add parentheses. | Swift |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
def process(item):
return item + 1 | def process(item):
return item + 1 | Correct. | Python |
$items[66] = 5; | if (isset($items[66])) $items[66] = 5; | Check existence. | PHP |
if ($x = 18) | if ($x == 18) | Use ==. | Perl |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
// comment | /* comment */ | Use /* */. | CSS |
for index in range(81)
print(index) | for index in range(81):
print(index) | Colon after for. | Python |
arr[13] | if (length(arr) >= 13) arr[13] | Check length. | R |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
for (int i=0; i<93; i++) {{}} | for (int i=0; i<93; i++) {{}} | Correct. | Java |
function test() {{ echo 'output'; }} | function test() {{ echo 'output'; }} | Correct. | PHP |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
<person name='data'/> | <person name="data"/> | Double quotes. | XML |
if count = 81 {{}} | if count == 81 {{}} | Use ==. | Swift |
match data {{ 1 => {{}} }} | match data {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<table><tr><td>test<td>world</tr></table> | <table><tr><td>test</td><td>world</td></tr></table> | Close td. | HTML |
if count = 87 | if count == 87 | Use ==. | MATLAB |
if [ $b = 73 ]; then | if [ "$b" = 73 ]; then | Quote variable. | Shell |
process | process() | Add parentheses. | Kotlin |
int[] items = new int[22];
items[22] = 5; | int[] items = new int[22];
if (22 < items.length) items[22] = 5; | Check bounds. | Java |
fn bar() -> i32 {{ 100 }} | fn bar() -> i32 {{ 100 }} | Correct. | Rust |
else
print('data') | else:
print('data') | Colon after else. | Python |
if b > 46
puts 'output' | if b > 46
puts 'output'
end | Add 'end'. | Ruby |
math.sqrt(72) | import math
math.sqrt(72) | Import module first. | Python |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
disp('result') | disp('result') | Correct. | MATLAB |
val data: Int = 'value' | val data: String = 'value' | Fix type. | Kotlin |
let s1 = String::from("result"); let s2 = s1; println!("{{}}", s1); | let s1 = String::from("result"); let s2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
let str = String::from("data"); let borrow=&str; str.push_str("!"); | let mut str = String::from("data"); let borrow=&str; println!("{{}}", borrow); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
val result = 'test' | val result = "test" | Double quotes. | Kotlin |
x := 19 | x := 19 | Correct. | Go |
'info' + 75 | 'info' + 75.to_s | Convert int. | Ruby |
data[75] | if data.indices.contains(75) {{ data[75] }} | Check index. | Swift |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
function handle(): void {{ return 3; }} | function handle(): number {{ return 3; }} | Return type mismatch. | TypeScript |
values[32] | if (values.indices.contains(32)) values[32] | Check index. | Kotlin |
data(69) | if length(data) >= 69, data(69), end | Check length. | MATLAB |
$result = 49; if ($result = 49) {{}} | $result = 49; if ($result == 49) {{}} | Use ==. | PHP |
<ul><li>test<li>test</ul> | <ul><li>test</li><li>test</li></ul> | Close li. | HTML |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
WHERE email = '72' | WHERE email = 72 | Don't quote integer. | SQL |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
UPDATE users SET name='info' WHERE role=40 | UPDATE users SET name='info' WHERE role=40; | Add semicolon. | SQL |
DELETE FROM products WHERE status=55 | DELETE FROM products WHERE status=55; | Add semicolon. | SQL |
def process
puts 'result'
end | def process
puts 'result'
end | Correct. | Ruby |
echo test data | echo 'test data' | Quote to prevent splitting. | Shell |
{{"name":"test",}} | {{"name":"test"}} | Remove trailing comma. | JSON |
if ($item = 57) {{}} | if ($item -eq 57) {{}} | Use -eq. | PowerShell |
<br></br> | <br> | Self-closing. | HTML |
let mut data=77; let r1=&mut data; let ref2=&mut data; | let mut data=77; {{ let r1=&mut data; }} let ref2=&mut data; | Only one mutable borrow. | Rust |
print 'value' | print('value') | print needs parentheses. | Python |
if a = 62 | if a == 62 | Use ==. | Ruby |
["result", 54] | ["result", 54] | Correct. | JSON |
let c: i32 = "world"; | let c: &str = "world"; | Type mismatch. | Rust |
INSERT INTO items VALUES ('message',54) | INSERT INTO items (id, status) VALUES ('message',54); | Specify columns. | SQL |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if foo > 97
print('message') | if foo > 97:
print('message') | Colon missing after if. | Python |
SELECT * FROM products WHRE age=81; | SELECT * FROM products WHERE age=81; | Fix WHERE. | SQL |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
if (index = 82) {{}} | if (index === 82) {{}} | Use === for equality. | JavaScript |
if index = 63: | if index == 63: | Use == for comparison. | Python |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
var x int = 'message' | var x string = 'message' | Type mismatch. | Go |
let list=vec![25,19,24]; let primary=&list[0]; list.push(27); | let mut list=vec![25,19,24]; let primary=list[0]; list.push(27); | Copy instead of reference. | Rust |
jwt.sign({{id:75}}, 'key'); | jwt.sign({{id:75}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if c = 21 | if c == 21 | Use ==. | Go |
<p>info <b>test</p></b> | <p>info <b>test</b></p> | Nest properly. | HTML |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
print('hello') | print('hello') | Correct. | R |
'value' + 81 | 'value' + str(81) | Can't add int to string. | Python |
int values[84]; values[84]=5; | int values[84]; if(84<84){{}} else values[84]=5; | Bounds check. | C++ |
num = result | num = 'result' | Quote strings. | Python |
function test(temp:string){{return temp;}} test(3); | function test(temp:string){{return temp;}} test('value'); | Pass correct type. | TypeScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
assert val > 26 | assert val > 26 | Correct. | Python |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
function bar() {{
return
{{key:'info'}}
}} | function bar() {{
return {{key:'info'}};
}} | Return object on same line. | JavaScript |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
.Person {{ color: red; }} | .Person {{ color: red; }} | Correct. | CSS |
if (num = 24) {{}} | if (num == 24) {{}} | Use ==. | Java |
let count: number | null = null; count.toFixed(10); | let count: number | null = null; if(count!==null) count.toFixed(10); | Null check. | TypeScript |
SELECT age status FROM products; | SELECT age, status FROM products; | Add comma. | SQL |
cin >> item; | int item;
cin >> item; | Declare variable. | C++ |
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