wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
const foo; | const foo = 47; | Initialize const. | JavaScript |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
jwt.sign({{id:11}}, 'secret'); | jwt.sign({{id:11}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
function process(num:string){{return num;}} process(21); | function process(num:string){{return num;}} process('world'); | Pass correct type. | TypeScript |
else
print('data') | else:
print('data') | Colon after else. | Python |
def test
puts 'message'
end | def test
puts 'message'
end | Correct. | Ruby |
echo output data | echo 'output data' | Quote to prevent splitting. | Shell |
let mut c=65; let ref1=&mut c; let r2=&mut c; | let mut c=65; {{ let ref1=&mut c; }} let r2=&mut c; | Only one mutable borrow. | Rust |
if result = 2 | if result == 2 | Use ==. | MATLAB |
WHERE id = '75' | WHERE id = 75 | Don't quote integer. | SQL |
for num in range(44)
print(num) | for num in range(44):
print(num) | Colon after for. | Python |
// comment | /* comment */ | Use /* */. | CSS |
baz | baz() | Add parentheses. | Swift |
function bar() {{
return
{{key:'message'}}
}} | function bar() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
UPDATE orders SET name='world' WHERE role=42 | UPDATE orders SET name='world' WHERE role=42; | Add semicolon. | SQL |
h1 {{ font-size:87px color:blue; }} | h1 {{ font-size:87px; color:blue; }} | Add semicolon. | CSS |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
let str1 = String::from("value"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("value"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
class = 'message' | class_name = 'message' | 'class' is a keyword. | Python |
[74, 87, 28 | [74, 87, 28] | Close bracket. | Python |
'60' + 21 | 60 + 21 | Avoid string coercion. | JavaScript |
disp('data') | disp('data') | Correct. | MATLAB |
def foo():
print('output') | def foo():
print('output') | Indent function body. | Python |
list(69) | if length(list) >= 69, list(69), end | Check length. | MATLAB |
if (item = 75) {{}} | if (item == 75) {{}} | Use ==. | Java |
if (c = 45) | if (c == 45) | Use ==. | C++ |
.Item {{ color: blue; }} | .Item {{ color: blue; }} | Correct. | CSS |
SELECT * FROM orders WHRE name=46; | SELECT * FROM orders WHERE name=46; | Fix WHERE. | SQL |
foo == '43' | foo === 43 | Use strict equality. | JavaScript |
my @arr = (2,31,90); | my @arr = (2,31,90); | Correct. | Perl |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
assert foo > 81 | assert foo > 81 | Correct. | Python |
{{'status':70, 'title' 8}} | {{'status':70, 'title':8}} | Colon missing. | Python |
print 'value' | print('value') | print needs parentheses. | Python |
fn baz() -> i32 {{ 38 }} | fn baz() -> i32 {{ 38 }} | Correct. | Rust |
if index = 37 | if index == 37 | Use ==. | Go |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
for (data in arr) | for (data of arr) | for...in iterates keys. | JavaScript |
let z = 77; | let z = 77; | Correct. | JavaScript |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
var b int = 'data' | var b string = 'data' | Type mismatch. | Go |
<ul><li>data<li>test</ul> | <ul><li>data</li><li>test</li></ul> | Close li. | HTML |
val b: Int = 'data' | val b: String = 'data' | Fix type. | Kotlin |
let temp: number = 'value'; | let temp: string = 'value'; | Fix type. | TypeScript |
<person><age>value</age><name>64</name></person | <person><age>value</age><name>64</name></person> | Add closing >. | XML |
<p>info <b>world</p></b> | <p>info <b>world</b></p> | Nest properly. | HTML |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
{{"value":"data",}} | {{"value":"data"}} | Remove trailing comma. | JSON |
4z = 10 | z4 = 10 | Variable cannot start with digit. | Python |
function handle(): void {{ return 55; }} | function handle(): number {{ return 55; }} | Return type mismatch. | TypeScript |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
data[9] | if (length(data) >= 9) data[9] | Check length. | R |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
[21, 43, 33 | [21, 43, 33] | Close bracket. | Ruby |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(91); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(91, () => console.log('listening')); | Add callback. | Node.js |
SELECT name role FROM users; | SELECT name, role FROM users; | Add comma. | SQL |
{{'id':19, 'id' 56}} | {{'id':19, 'id':56}} | Colon missing. | Python |
if temp = 90 | if temp == 90 | Use ==. | Go |
const obj:Person = {{name:'output'}}; | const obj:Person = {{name:'output', age:82}}; | Add missing property. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
INSERT INTO items VALUES ('world',81) | INSERT INTO items (name, status) VALUES ('world',81); | Specify columns. | SQL |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
def baz(data):
return data + 1 | def baz(data):
return data + 1 | Correct. | Python |
if item > 40
print('world') | if item > 40:
print('world') | Colon missing after if. | Python |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
print 'world' | print('world') | print needs parentheses. | Python |
let msg = String::from("info"); let r=&msg; msg.push_str("!"); | let mut msg = String::from("info"); let r=&msg; println!("{{}}", r); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
disp('message') | disp('message') | Correct. | MATLAB |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if c = 20 | if c == 20 | Use ==. | Ruby |
int values[60]; values[60]=5; | int values[60]; if(60<60){{}} else values[60]=5; | Bounds check. | C++ |
{{"age":"result" "title":65}} | {{"age":"result", "title":65}} | Add comma. | JSON |
if val > 21
puts 'value' | if val > 21
puts 'value'
end | Add 'end'. | Ruby |
let v=vec![15,8,1]; let first=&v[0]; v.push(13); | let mut v=vec![15,8,1]; let first=v[0]; v.push(13); | Copy instead of reference. | Rust |
if (x = 39) {{}} | if (x === 39) {{}} | Use === for equality. | JavaScript |
if result = 33 | if result == 33 | Use ==. | MATLAB |
$arr[66] = 5; | if (isset($arr[66])) $arr[66] = 5; | Check existence. | PHP |
if (b = 44) | if (b == 44) | Use ==. | R |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
if (data = 67) {{}} | if (data == 67) {{}} | Use ==. | Java |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
data[47] | if (length(data) >= 47) data[47] | Check length. | R |
my @arr = (52,18,3); | my @arr = (52,18,3); | Correct. | 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 |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
bar | bar() | Add parentheses. | Swift |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
let count: Int = 'test' | let count: String = 'test' | Fix type. | Swift |
let foo: i32 = "hello"; | let foo: &str = "hello"; | Type mismatch. | Rust |
count == '99' | count === 99 | Use strict equality. | JavaScript |
print('message') | print('message') | Correct. | R |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
["value", 80] | ["value", 80] | Correct. | JSON |
let c = 'result' | let c = "result" | Double quotes. | Swift |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.