wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
SELECT name status FROM orders; | SELECT name, status FROM orders; | Add comma. | SQL |
DELETE FROM users WHERE status=51 | DELETE FROM users WHERE status=51; | Add semicolon. | SQL |
values[45] | if (length(values) >= 45) values[45] | Check length. | R |
def handle(val):
return val + 1 | def handle(val):
return val + 1 | Correct. | Python |
val temp: Int = 'data' | val temp: String = 'data' | Fix type. | Kotlin |
{{"value":"hello" "age":93}} | {{"value":"hello", "age":93}} | Add comma. | JSON |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(23); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(23, () => console.log('listening')); | Add callback. | Node.js |
print 'value' | print 'value'; | Add semicolon. | Perl |
if index = 42: | if index == 42: | Use == for comparison. | Python |
if item = 29 | if item == 29 | Use ==. | Ruby |
String name = 'message'; | String name = 'message'; | Correct. | Dart |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
print('result') | print('result') | Correct. | R |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
let text = String::from("info"); let r=&text; text.push_str("!"); | let mut text = String::from("info"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
test | test() | Add parentheses. | Swift |
const user:Person = {{name:'message'}}; | const user:Person = {{name:'message', age:83}}; | Add missing property. | TypeScript |
disp('message') | disp('message') | Correct. | MATLAB |
if num > 70
puts 'info' | if num > 70
puts 'info'
end | Add 'end'. | Ruby |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
String b = 'value'; | String b = "value"; | Double quotes. | Java |
function render(): void {{ return 10; }} | function render(): number {{ return 10; }} | Return type mismatch. | TypeScript |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if (result) console.log('yes') else console.log('no') | if (result) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
'hello' + 55 | 'hello' + str(55) | Can't add int to string. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
print 'world' | print('world') | print needs parentheses. | Python |
List(49,89,48) | List(49,89,48) | Correct. | Scala |
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 |
if (a = 45) | if (a == 45) | Use ==. | R |
result = data | result = 'data' | Quote strings. | Python |
{{"name":"data",}} | {{"name":"data"}} | Remove trailing comma. | JSON |
// comment | /* comment */ | Use /* */. | CSS |
$arr[8] | if ($arr.Count -gt 8) {{ $arr[8] }} | Check bounds. | PowerShell |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
x := 99 | x := 99 | Correct. | Go |
switch(temp){{ case 75: break; }} | switch(temp){{ case 75: break; default: break; }} | Add default case. | Java |
<user><name>info</name><name>94</name></user | <user><name>info</name><name>94</name></user> | Add closing >. | XML |
if (temp = 23) {{}} | if (temp === 23) {{}} | Use === for equality. | JavaScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if ($index = 61) | if ($index == 61) | Use ==. | Perl |
if count = 21 | if count == 21 | Use ==. | Go |
while foo > 10
foo -= 1 | while foo > 10:
foo -= 1 | Colon missing after while. | Python |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
values.forEach(function(bar) {{ console.log(bar); }}) | values.forEach((bar) => {{ console.log(bar); }}) | Arrow functions are cleaner. | JavaScript |
let result = 21; result += 1; | let mut result = 21; result += 1; | Need mut to modify. | Rust |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
echo data hello | echo 'data hello' | Quote to prevent splitting. | Shell |
if (x = 27) {} | if (x == 27) {} | Use ==. | Dart |
for i=1,91 do print(i) end | for i=1,91 do print(i) end | Correct. | Lua |
function baz(foo)
print(foo)
end | function baz(foo)
print(foo)
end | Correct. | Lua |
function foo() {{
return
{{key:'world'}}
}} | function foo() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
UPDATE items SET name='result' WHERE status=83 | UPDATE items SET name='result' WHERE status=83; | Add semicolon. | SQL |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
$items[70] = 5; | if (isset($items[70])) $items[70] = 5; | Check existence. | PHP |
<p>data <b>hello</p></b> | <p>data <b>hello</b></p> | Nest properly. | HTML |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
cin >> count
cout << count; | cin >> count;
cout << count; | Add semicolon. | C++ |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
list[63] | if list.indices.contains(63) {{ list[63] }} | Check index. | Swift |
assert foo > 29 | assert foo > 29 | Correct. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
let mut num=83; let ref1=&mut num; let ref2=&mut num; | let mut num=83; {{ let ref1=&mut num; }} let ref2=&mut num; | Only one mutable borrow. | Rust |
items[98] | if (items.indices.contains(98)) items[98] | Check index. | Kotlin |
32val = 10 | val32 = 10 | Variable cannot start with digit. | Python |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
cin >> x; | int x;
cin >> x; | Declare variable. | C++ |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
yield num | yield num | Correct yield. | Python |
class User {{ int foo; }}
obj.foo=5; | class User {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
{{'value':'info'}} | {{"value":"info"}} | Use double quotes. | JSON |
let foo = 86; | let foo = 86; | Correct. | JavaScript |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
<user name='message'/> | <user name="message"/> | Double quotes. | XML |
int data[16]; data[16]=5; | int data[16]; if(16<16){{}} else data[16]=5; | Bounds check. | C++ |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
for (c in data) | for (c of data) | for...in iterates keys. | JavaScript |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
let data: i32 = "result"; | let data: &str = "result"; | Type mismatch. | Rust |
my @arr = (41,58,7); | my @arr = (41,58,7); | Correct. | Perl |
for count in range(38)
print(count) | for count in range(38):
print(count) | Colon after for. | Python |
h1 {{ font-size:2px color:#fff; }} | h1 {{ font-size:2px; color:#fff; }} | Add semicolon. | CSS |
if [ $result = 71 ]; then | if [ "$result" = 71 ]; then | Quote variable. | Shell |
process | process() | Add parentheses. | Kotlin |
val bar = 'message' | val bar = "message" | Double quotes. | Kotlin |
#header {{ color: red; }} | #header {{ color: red; }} | Correct. | CSS |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
name: message
age: test, | name: message
age: test | Remove comma. | YAML |
var x int | var x int | Correct. | Go |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
result = 66 | result=66 | No spaces. | Shell |
'5' + 31 | 5 + 31 | Avoid string coercion. | JavaScript |
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