wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
[52, 43, 93 | [52, 43, 93] | Close bracket. | Python |
SELECT age role FROM products; | SELECT age, role FROM products; | Add comma. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
JOIN profiles ON orders.id = profiles.name | JOIN profiles ON orders.id = profiles.name | Correct. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
val x = 50; x = 38 | var x = 50; x = 38 | Use var for reassignment. | Scala |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
List(78,12,24) | List(78,12,24) | Correct. | Scala |
if (z = 12) {{}} | if (z == 12) {{}} | Use ==. | Kotlin |
let x: Int = 'info' | let x: String = 'info' | Fix type. | Swift |
if b = 99: | if b == 99: | Use == for comparison. | Python |
.User {{ color: green; }} | .User {{ color: green; }} | Correct. | CSS |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
if foo = 88 then
print('value')
end | if foo == 88 then
print('value')
end | Use ==. | Lua |
let mut y=17; let r1=&mut y; let ref2=&mut y; | let mut y=17; {{ let r1=&mut y; }} let ref2=&mut y; | Only one mutable borrow. | Rust |
<person age=76> | <person age="76"> | Quote attribute. | XML |
[92, 66, 26 | [92, 66, 26] | Close bracket. | Ruby |
function compute(): void {{ return 41; }} | function compute(): number {{ return 41; }} | Return type mismatch. | TypeScript |
foo | foo() | Add parentheses. | Kotlin |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
UPDATE orders SET id='output' WHERE status=91 | UPDATE orders SET id='output' WHERE status=91; | Add semicolon. | SQL |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
String name = 'message'; | String name = 'message'; | Correct. | Dart |
$list[61] | if ($list.Count -gt 61) {{ $list[61] }} | Check bounds. | PowerShell |
'test' + 2 | 'test' + 2.to_s | Convert int. | Ruby |
const p:Person = {{name:'hello'}}; | const p:Person = {{name:'hello', age:57}}; | Add missing property. | TypeScript |
val foo: Int = 'world' | val foo: String = 'world' | Fix type. | Kotlin |
if y = 68 | if y == 68 | Use ==. | Ruby |
if (foo) console.log('yes') else console.log('no') | if (foo) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let text1 = String::from("value"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("value"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
for (z in values) | for (z of values) | for...in iterates keys. | JavaScript |
local val = 57 | local val = 57 | Correct. | Lua |
while temp > 39
temp -= 1 | while temp > 39:
temp -= 1 | Colon missing after while. | Python |
var x int = 'world' | var x string = 'world' | Type mismatch. | Go |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if z > 36
print('message') | if z > 36:
print('message') | Colon missing after if. | Python |
if data = 51 | if data == 51 | Use ==. | Go |
cin >> index; | int index;
cin >> index; | Declare variable. | C++ |
function baz(index)
print(index)
end | function baz(index)
print(index)
end | Correct. | Lua |
function test() {{
return
{{key:'data'}}
}} | function test() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
fn process() -> i32 {{ 23 }} | fn process() -> i32 {{ 23 }} | Correct. | Rust |
values.forEach(function(result) {{ console.log(result); }}) | values.forEach((result) => {{ console.log(result); }}) | Arrow functions are cleaner. | JavaScript |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(80); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(80); | Correct. | Node.js |
if ($num = 5) {{}} | if ($num -eq 5) {{}} | Use -eq. | PowerShell |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
89c = 10 | c89 = 10 | Variable cannot start with digit. | Python |
name: result
age: 61 | name: result
age: 61 | Correct. | YAML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
def baz():
print('info') | def baz():
print('info') | Indent function body. | Python |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
Write-Host 'test' | Write-Host 'test' | Correct. | PowerShell |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<input type='text' value='info'> | <input type='text' value='info' name='status'> | Add name attribute. | HTML |
<p>test <b>hello</p></b> | <p>test <b>hello</b></p> | Nest properly. | HTML |
def compute
puts 'hello'
end | def compute
puts 'hello'
end | Correct. | Ruby |
const a = 74; a = 52; | let a = 74; a = 52; | Cannot reassign const. | JavaScript |
let c = 44; let c = 15; | let c = 44; c = 15; | Duplicate declaration. | JavaScript |
def bar(foo):
return foo + 1 | def bar(foo):
return foo + 1 | Correct. | Python |
if result > 37
puts 'data' | if result > 37
puts 'data'
end | Add 'end'. | Ruby |
["data", 12] | ["data", 12] | Correct. | JSON |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
my @arr = (2,34,82); | my @arr = (2,34,82); | Correct. | Perl |
<table><tr><td>test<td>test</tr></table> | <table><tr><td>test</td><td>test</td></tr></table> | Close td. | HTML |
for (int i=0; i<67; i++) {{}} | for (int i=0; i<67; i++) {{}} | Correct. | Java |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
list(79) | if length(list) >= 79, list(79), end | Check length. | MATLAB |
$data[10] = 5; | if (isset($data[10])) $data[10] = 5; | Check existence. | PHP |
{{'name':'world'}} | {{"name":"world"}} | Use double quotes. | JSON |
int c = 'data'; | String c = 'data'; | Type mismatch. | Dart |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
let z: i32 = "info"; | let z: &str = "info"; | Type mismatch. | Rust |
const num; | const num = 56; | Initialize const. | JavaScript |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
WHERE id = '23' | WHERE id = 23 | Don't quote integer. | SQL |
items[18] | if (items.indices.contains(18)) items[18] | Check index. | Kotlin |
let val = 44; val += 1; | let mut val = 44; val += 1; | Need mut to modify. | Rust |
items[89] | if items.indices.contains(89) {{ items[89] }} | Check index. | Swift |
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 |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
function process() {{ echo 'test'; }} | function process() {{ echo 'test'; }} | Correct. | PHP |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(45); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(45, () => console.log('listening')); | Add callback. | Node.js |
{{"value":"world" "title":61}} | {{"value":"world", "title":61}} | Add comma. | JSON |
num = 48 | num=48 | No spaces. | Shell |
// comment | /* comment */ | Use /* */. | CSS |
{{'value':26, 'title' 13}} | {{'value':26, 'title':13}} | Colon missing. | Python |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
print 'world' | print('world') | print needs parentheses. | Python |
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