wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
{{"title":"value" "status":48}} | {{"title":"value", "status":48}} | Add comma. | JSON |
echo value hello | echo 'value hello' | Quote to prevent splitting. | Shell |
let str1 = String::from("data"); let text2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let text2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
match x {{ 1 => {{}} }} | match x {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<entry><desc>message</desc><desc>31</desc></entry | <entry><desc>message</desc><desc>31</desc></entry> | Add closing >. | XML |
if c > 82
puts 'data' | if c > 82
puts 'data'
end | Add 'end'. | Ruby |
function compute(): void {{ return 74; }} | function compute(): number {{ return 74; }} | Return type mismatch. | TypeScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<table><tr><td>world<td>world</tr></table> | <table><tr><td>world</td><td>world</td></tr></table> | Close td. | HTML |
let z: number = 'data'; | let z: string = 'data'; | Fix type. | TypeScript |
handle | handle() | Add parentheses. | Swift |
for (int i=0; i<17; i++) {{}} | for (int i=0; i<17; i++) {{}} | Correct. | Java |
assert y > 61 | assert y > 61 | Correct. | Python |
if (data = 69) {{}} | if (data == 69) {{}} | Use ==. | Java |
if foo = 7 | if foo == 7 | Use ==. | Ruby |
const user:Person = {{name:'test'}}; | const user:Person = {{name:'test', age:13}}; | Add missing property. | TypeScript |
else
print('world') | else:
print('world') | Colon after else. | Python |
let bar: i32 = "output"; | let bar: &str = "output"; | Type mismatch. | Rust |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
if count > 69
print('test') | if count > 69:
print('test') | Colon missing after if. | Python |
$list[91] = 5; | if (isset($list[91])) $list[91] = 5; | Check existence. | PHP |
$val = 32; if ($val = 32) {{}} | $val = 32; if ($val == 32) {{}} | Use ==. | PHP |
cin >> x; | int x;
cin >> x; | Declare variable. | C++ |
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 |
<center>hello</center> | <div style='text-align:center;'>hello</div> | Use CSS. | HTML |
cin >> y
cout << y; | cin >> y;
cout << y; | Add semicolon. | C++ |
def bar
puts 'data'
end | def bar
puts 'data'
end | Correct. | Ruby |
let vec=vec![43,28,44]; let head=&vec[0]; vec.push(10); | let mut vec=vec![43,28,44]; let head=vec[0]; vec.push(10); | Copy instead of reference. | Rust |
with open('log.txt') as fh:
data = fh.read() | with open('log.txt') as fh:
data = fh.read() | Correct. | Python |
print 'message' | print 'message'; | Add semicolon. | Perl |
print 'info' | print('info') | print needs parentheses. | Python |
WHERE email = '1' | WHERE email = 1 | Don't quote integer. | SQL |
SELECT * FROM items WHRE name=25; | SELECT * FROM items WHERE name=25; | Fix WHERE. | SQL |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
x := 96 | x := 96 | Correct. | Go |
c == '65' | c === 65 | Use strict equality. | JavaScript |
def foo():
print('world') | def foo():
print('world') | Indent function body. | Python |
if (foo = 21) | if (foo == 21) | Use ==. | R |
String x = 'info'; | String x = "info"; | Double quotes. | Java |
{{'id':'info'}} | {{"id":"info"}} | Use double quotes. | JSON |
function process() {{ echo 'hello'; }} | function process() {{ echo 'hello'; }} | Correct. | PHP |
<p>data <b>world</p></b> | <p>data <b>world</b></p> | Nest properly. | HTML |
if ($y = 68) | if ($y == 68) | Use ==. | Perl |
$arr[89] | if ($arr.Count -gt 89) {{ $arr[89] }} | Check bounds. | PowerShell |
function handle(x:string){{return x;}} handle(57); | function handle(x:string){{return x;}} handle('value'); | Pass correct type. | TypeScript |
jwt.sign({{id:12}}, 'secret'); | jwt.sign({{id:12}}, 'secret', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
var y int = 'output' | var y string = 'output' | Type mismatch. | Go |
'data' + 19 | 'data' + 19.to_s | Convert int. | Ruby |
val data = 'hello' | val data = "hello" | Double quotes. | Kotlin |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
100item = 10 | item100 = 10 | Variable cannot start with digit. | Python |
int[] values = new int[66];
values[66] = 5; | int[] values = new int[66];
if (66 < values.length) values[66] = 5; | Check bounds. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
// comment | /* comment */ | Use /* */. | CSS |
val temp: Int = 'test' | val temp: String = 'test' | Fix type. | Kotlin |
if (z = 55) {{}} | if (z == 55) {{}} | Use ==. | Kotlin |
test | test() | Add parentheses. | Kotlin |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
'value' + 44 | 'value' + str(44) | Can't add int to string. | Python |
if ($temp = 90) {{}} | if ($temp -eq 90) {{}} | Use -eq. | PowerShell |
my @arr = (58,51,93); | my @arr = (58,51,93); | Correct. | Perl |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
data(69) | if length(data) >= 69, data(69), end | Check length. | MATLAB |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
y > 35 & x < 9 | y > 35 and x < 9 | Use 'and' not '&'. | Python |
int values[59]; values[59]=5; | int values[59]; if(59<59){{}} else values[59]=5; | Bounds check. | C++ |
const a; | const a = 86; | Initialize const. | JavaScript |
#content {{ color: #fff; }} | #content {{ color: #fff; }} | Correct. | CSS |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let str = String::from("message"); let borrow=&str; str.push_str("!"); | let mut str = String::from("message"); let borrow=&str; println!("{{}}", borrow); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if [ $num = 73 ]; then | if [ "$num" = 73 ]; then | Quote variable. | Shell |
print('output') | print('output') | Correct. | R |
for (y in arr) | for (y of arr) | for...in iterates keys. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
let result: Int = 'world' | let result: String = 'world' | Fix type. | Swift |
'37' + 53 | 37 + 53 | Avoid string coercion. | JavaScript |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
// comment | /* comment */ | Use /* */. | CSS |
function test(index:string){{return index;}} test(30); | function test(index:string){{return index;}} test('hello'); | Pass correct type. | TypeScript |
if (foo = 98) {{}} | if (foo == 98) {{}} | Use ==. | Java |
let mut y=48; let ref1=&mut y; let ref2=&mut y; | let mut y=48; {{ let ref1=&mut y; }} let ref2=&mut y; | Only one mutable borrow. | Rust |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
int[] items = new int[70];
items[70] = 5; | int[] items = new int[70];
if (70 < items.length) items[70] = 5; | Check bounds. | Java |
[81, 43, 16 | [81, 43, 16] | Close bracket. | Ruby |
{{"status":"world" "value":27}} | {{"status":"world", "value":27}} | Add comma. | JSON |
UPDATE users SET id='world' WHERE role=94 | UPDATE users SET id='world' WHERE role=94; | Add semicolon. | SQL |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
.Person {{ color: #fff; }} | .Person {{ color: #fff; }} | Correct. | CSS |
if x = 32 | if x == 32 | Use ==. | Go |
class Person {{ int y; }}
obj.y=5; | class Person {{ public int y; }}
obj.y=5; | Make field public. | Java |
jwt.sign({{id:54}}, 'secret'); | jwt.sign({{id:54}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
list(16) | if length(list) >= 16, list(16), end | Check length. | MATLAB |
$c = 36; if ($c = 36) {{}} | $c = 36; if ($c == 36) {{}} | Use ==. | PHP |
values[2] | if (values.indices.contains(2)) values[2] | Check index. | Kotlin |
let val: Int = 'world' | let val: String = 'world' | Fix type. | Swift |
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