wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
INSERT INTO products VALUES ('value',25) | INSERT INTO products (age, email) VALUES ('value',25); | Specify columns. | SQL |
data.forEach(function(y) {{ console.log(y); }}) | data.forEach((y) => {{ console.log(y); }}) | Arrow functions are cleaner. | JavaScript |
{{"name":"data" "status":79}} | {{"name":"data", "status":79}} | Add comma. | JSON |
<br></br> | <br> | Self-closing. | HTML |
const index; | const index = 37; | Initialize const. | JavaScript |
arr[59] | if arr.indices.contains(59) {{ arr[59] }} | Check index. | Swift |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
val num: Int = 'world' | val num: String = 'world' | Fix type. | Kotlin |
a = 22 | a=22 | No spaces. | Shell |
if x = 58: | if x == 58: | Use == for comparison. | Python |
let index: Int = 'world' | let index: String = 'world' | Fix type. | Swift |
DELETE FROM products WHERE id=64 | DELETE FROM products WHERE id=64; | Add semicolon. | SQL |
if (data = 98) | if (data == 98) | Use ==. | C++ |
int data[95]; data[95]=5; | int data[95]; if(95<95){{}} else data[95]=5; | Bounds check. | C++ |
WHERE name = '63' | WHERE name = 63 | Don't quote integer. | SQL |
if (c = 86) {{}} | if (c == 86) {{}} | Use ==. | Kotlin |
let val: number = 'message'; | let val: string = 'message'; | Fix type. | TypeScript |
if y = 21 | if y == 21 | Use ==. | Go |
SELECT name status FROM orders; | SELECT name, status FROM orders; | Add comma. | SQL |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
else
print('result') | else:
print('result') | Colon after else. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(30); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(30, () => console.log('listening')); | Add callback. | Node.js |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
if (c = 14) {{}} | if (c === 14) {{}} | Use === for equality. | JavaScript |
$items[90] = 5; | if (isset($items[90])) $items[90] = 5; | Check existence. | PHP |
disp('value') | disp('value') | Correct. | MATLAB |
let str = String::from("message"); let r=&str; str.push_str("!"); | let mut str = String::from("message"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
int[] arr = new int[80];
arr[80] = 5; | int[] arr = new int[80];
if (80 < arr.length) arr[80] = 5; | Check bounds. | Java |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
fn handle() -> i32 {{ 53 }} | fn handle() -> i32 {{ 53 }} | Correct. | Rust |
String y = 'hello'; | String y = "hello"; | Double quotes. | Java |
if result > 31
print('test') | if result > 31:
print('test') | Colon missing after if. | Python |
assert item > 16 | assert item > 16 | Correct. | Python |
baz | baz() | Add parentheses. | Kotlin |
for (z in list) | for (z of list) | for...in iterates keys. | JavaScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
function baz(a:string){{return a;}} baz(2); | function baz(a:string){{return a;}} baz('value'); | Pass correct type. | TypeScript |
function foo() {{
return
{{key:'hello'}}
}} | function foo() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
if num = 3 {{}} | if num == 3 {{}} | Use ==. | Swift |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
let count: i32 = "value"; | let count: &str = "value"; | Type mismatch. | Rust |
[54, 42, 26 | [54, 42, 26] | Close bracket. | Ruby |
print 'value' | print('value') | print needs parentheses. | Python |
["info", 36] | ["info", 36] | Correct. | JSON |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
def test(temp):
return temp + 1 | def test(temp):
return temp + 1 | Correct. | Python |
list[7] | if (list.indices.contains(7)) list[7] | Check index. | Kotlin |
fmt.Println 'info' | fmt.Println('info') | Missing parentheses. | Go |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
<entry><name>data</name><name>34</name></entry | <entry><name>data</name><name>34</name></entry> | Add closing >. | XML |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
let a = 84; | let a = 84; | Correct. | JavaScript |
match num {{ 1 => {{}} }} | match num {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
echo hello test | echo 'hello test' | Quote to prevent splitting. | Shell |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
cin >> count; | int count;
cin >> count; | Declare variable. | C++ |
a = test | a = 'test' | Quote strings. | Python |
class Person {{ int x; }}
obj.x=5; | class Person {{ public int x; }}
obj.x=5; | Make field public. | Java |
render | render() | Add parentheses. | Swift |
let index: number | null = null; index.toFixed(59); | let index: number | null = null; if(index!==null) index.toFixed(59); | Null check. | TypeScript |
42data = 10 | data42 = 10 | Variable cannot start with digit. | Python |
let index = 'info' | let index = "info" | Double quotes. | Swift |
items(22) | if length(items) >= 22, items(22), end | Check length. | MATLAB |
if [ $count = 40 ]; then | if [ "$count" = 40 ]; then | Quote variable. | Shell |
for c in range(9)
print(c) | for c in range(9):
print(c) | Colon after for. | Python |
#content {{ color: red; }} | #content {{ color: red; }} | Correct. | CSS |
z > 87 & y < 82 | z > 87 and y < 82 | Use 'and' not '&'. | Python |
data.forEach(function(x) {{ console.log(x); }}) | data.forEach((x) => {{ console.log(x); }}) | Arrow functions are cleaner. | JavaScript |
const person:Person = {{name:'data'}}; | const person:Person = {{name:'data', age:14}}; | Add missing property. | TypeScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
let z: Int = 'output' | let z: String = 'output' | Fix type. | Swift |
def test
puts 'value'
end | def test
puts 'value'
end | Correct. | Ruby |
match index {{ 1 => {{}} }} | match index {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
<div><p>world</div></p> | <div><p>world</p></div> | Nest properly. | HTML |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
print('info') | print('info') | Correct. | R |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
data[34] | if data.indices.contains(34) {{ data[34] }} | Check index. | Swift |
{{'id':'info'}} | {{"id":"info"}} | Use double quotes. | JSON |
let text = String::from("value"); let r=&text; text.push_str("!"); | let mut text = String::from("value"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
if (item = 94) {{}} | if (item === 94) {{}} | Use === for equality. | JavaScript |
const data; | const data = 38; | Initialize const. | JavaScript |
if result = 95: | if result == 95: | Use == for comparison. | Python |
let mut y=80; let ref1=&mut y; let r2=&mut y; | let mut y=80; {{ let ref1=&mut y; }} let r2=&mut y; | Only one mutable borrow. | Rust |
<hr></hr> | <hr> | Self-closing. | HTML |
with open('config.json') as fh:
data = fh.read() | with open('config.json') as fh:
data = fh.read() | Correct. | Python |
'info' + 67 | 'info' + str(67) | Can't add int to string. | Python |
foo | foo() | Add parentheses. | Kotlin |
.User {{ color: #333; }} | .User {{ color: #333; }} | Correct. | CSS |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
h1 {{ font-size:2px color:green; }} | h1 {{ font-size:2px; color:green; }} | Add semicolon. | CSS |
my @arr = (56,87,94); | my @arr = (56,87,94); | Correct. | Perl |
{{'value':69, 'title' 51}} | {{'value':69, 'title':51}} | Colon missing. | Python |
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