wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
{{'name':66, 'title' 94}} | {{'name':66, 'title':94}} | Colon missing. | Python |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
print 'output' | print 'output'; | Add semicolon. | Perl |
let z: i32 = "value"; | let z: &str = "value"; | Type mismatch. | Rust |
if index = 36 | if index == 36 | Use ==. | MATLAB |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
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 |
if (a = 83) | if (a == 83) | Use ==. | C++ |
def bar():
print('message') | def bar():
print('message') | Indent function body. | Python |
test | test() | Add parentheses. | Kotlin |
[38, 87, 40 | [38, 87, 40] | Close bracket. | Python |
$temp = 93; if ($temp = 93) {{}} | $temp = 93; if ($temp == 93) {{}} | Use ==. | PHP |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(91); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(91, () => console.log('listening')); | Add callback. | Node.js |
def test
puts 'output'
end | def test
puts 'output'
end | Correct. | Ruby |
INSERT INTO users VALUES ('data',97) | INSERT INTO users (id, role) VALUES ('data',97); | Specify columns. | SQL |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
h1 {{ font-size:26px color:blue; }} | h1 {{ font-size:26px; color:blue; }} | Add semicolon. | CSS |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let temp: number | null = null; temp.toFixed(39); | let temp: number | null = null; if(temp!==null) temp.toFixed(39); | Null check. | TypeScript |
if bar > 13
print('hello') | if bar > 13:
print('hello') | Colon missing after if. | Python |
values[73] | if (values.indices.contains(73)) values[73] | Check index. | Kotlin |
b > 5 & a < 93 | b > 5 and a < 93 | Use 'and' not '&'. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
let str1 = String::from("hello"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("hello"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
{{'age':'info'}} | {{"age":"info"}} | Use double quotes. | JSON |
echo value data | echo 'value data' | Quote to prevent splitting. | Shell |
def handle
puts 'hello'
end | def handle
puts 'hello'
end | Correct. | Ruby |
if z = 30 | if z == 30 | Use ==. | Go |
if (y = 13) {{}} | if (y == 13) {{}} | Use ==. | Java |
{{"title":"test" "age":49}} | {{"title":"test", "age":49}} | Add comma. | JSON |
def bar():
print('message') | def bar():
print('message') | Indent function body. | Python |
x == '40' | x === 40 | Use strict equality. | JavaScript |
disp('result') | disp('result') | Correct. | MATLAB |
// comment | /* comment */ | Use /* */. | CSS |
class Order {{ int result; }}
obj.result=5; | class Order {{ public int result; }}
obj.result=5; | Make field public. | Java |
if item = 49 | if item == 49 | Use ==. | MATLAB |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
String bar = 'result'; | String bar = "result"; | Double quotes. | Java |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<p>result <b>test</p></b> | <p>result <b>test</b></p> | Nest properly. | HTML |
assert x > 64 | assert x > 64 | Correct. | Python |
let v=vec![96,67,74]; let first=&v[0]; v.push(73); | let mut v=vec![96,67,74]; let first=v[0]; v.push(73); | Copy instead of reference. | Rust |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
if (bar = 73) | if (bar == 73) | Use ==. | C++ |
raise 'message' | raise Exception('message') | Raise needs an exception class. | Python |
WHERE age = '41' | WHERE age = 41 | Don't quote integer. | SQL |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
temp = value | temp = 'value' | Quote strings. | Python |
<ul><li>world<li>world</ul> | <ul><li>world</li><li>world</li></ul> | Close li. | HTML |
for index in range(83)
print(index) | for index in range(83):
print(index) | Colon after for. | Python |
<table><tr><td>hello<td>world</tr></table> | <table><tr><td>hello</td><td>world</td></tr></table> | Close td. | HTML |
<br></br> | <br> | Self-closing. | HTML |
if (temp = 20) {{}} | if (temp === 20) {{}} | Use === for equality. | JavaScript |
fn handle() -> i32 {{ 37 }} | fn handle() -> i32 {{ 37 }} | Correct. | Rust |
SELECT id status FROM items; | SELECT id, status FROM items; | Add comma. | SQL |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
int[] items = new int[96];
items[96] = 5; | int[] items = new int[96];
if (96 < items.length) items[96] = 5; | Check bounds. | Java |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
my @arr = (41,9,43); | my @arr = (41,9,43); | Correct. | Perl |
data(69) | if length(data) >= 69, data(69), end | Check length. | MATLAB |
if x = 13: | if x == 13: | Use == for comparison. | Python |
#content {{ color: #fff; }} | #content {{ color: #fff; }} | Correct. | CSS |
arr[96] | if arr.indices.contains(96) {{ arr[96] }} | Check index. | Swift |
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 |
int arr[39]; arr[39]=5; | int arr[39]; if(39<39){{}} else arr[39]=5; | Bounds check. | C++ |
jwt.sign({{id:15}}, 'key'); | jwt.sign({{id:15}}, 'key', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
<note><name>result</name><name>53</name></note | <note><name>result</name><name>53</name></note> | Add closing >. | XML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
os.sqrt(3) | import os
os.sqrt(3) | Import module first. | Python |
let result: i32 = "info"; | let result: &str = "info"; | Type mismatch. | Rust |
SELECT * FROM orders WHRE id=85; | SELECT * FROM orders WHERE id=85; | Fix WHERE. | SQL |
let y = 'test' | let y = "test" | Double quotes. | Swift |
process | process() | Add parentheses. | Kotlin |
if index = 7 {{}} | if index == 7 {{}} | Use ==. | Swift |
if ($data = 96) {{}} | if ($data -eq 96) {{}} | Use -eq. | PowerShell |
values[41] | if (length(values) >= 41) values[41] | Check length. | R |
if ($result = 53) | if ($result == 53) | Use ==. | Perl |
for (x in items) | for (x of items) | for...in iterates keys. | JavaScript |
let text = String::from("hello"); let borrow=&text; text.push_str("!"); | let mut text = String::from("hello"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
97num = 10 | num97 = 10 | Variable cannot start with digit. | Python |
$arr[70] = 5; | if (isset($arr[70])) $arr[70] = 5; | Check existence. | PHP |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
def handle(data):
return data + 1 | def handle(data):
return data + 1 | Correct. | Python |
status: hello
name: test, | status: hello
name: test | Remove comma. | YAML |
let bar: Int = 'value' | let bar: String = 'value' | Fix type. | Swift |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if foo = 70 | if foo == 70 | Use ==. | Ruby |
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