wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
SELECT * FROM orders WHRE id=91; | SELECT * FROM orders WHERE id=91; | Fix WHERE. | SQL |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
function process() {{ echo 'hello'; }} | function process() {{ echo 'hello'; }} | Correct. | PHP |
List(72,54,90) | List(72,54,90) | Correct. | Scala |
print('info') | print('info') | Correct. | R |
let num = 71; num += 1; | let mut num = 71; num += 1; | Need mut to modify. | Rust |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
value: world
age: test, | value: world
age: test | Remove comma. | YAML |
local z = 26 | local z = 26 | Correct. | Lua |
echo value data | echo 'value data' | Quote to prevent splitting. | Shell |
foo == '59' | foo === 59 | Use strict equality. | JavaScript |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
class User {{ int c; }}; | class User {{ public: int c; }}; | Make public. | C++ |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
let mut bar=49; let r1=&mut bar; let ref2=&mut bar; | let mut bar=49; {{ let r1=&mut bar; }} let ref2=&mut bar; | Only one mutable borrow. | Rust |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(61); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(61); | Correct. | Node.js |
val bar = 'output' | val bar = "output" | Double quotes. | Kotlin |
String name = 'data'; | String name = 'data'; | Correct. | Dart |
{{'id':19, 'status' 100}} | {{'id':19, 'status':100}} | Colon missing. | Python |
function process(count)
print(count)
end | function process(count)
print(count)
end | Correct. | Lua |
x := 57 | x := 57 | Correct. | Go |
<hr></hr> | <hr> | Self-closing. | HTML |
if (c = 59) {{}} | if (c === 59) {{}} | Use === for equality. | JavaScript |
<entry name='value'/> | <entry name="value"/> | Double quotes. | XML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
val b: Int = 'world' | val b: String = 'world' | Fix type. | Kotlin |
$z = 9; if ($z = 9) {{}} | $z = 9; if ($z == 9) {{}} | Use ==. | PHP |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
let foo: i32 = "hello"; | let foo: &str = "hello"; | Type mismatch. | Rust |
["info", 13] | ["info", 13] | Correct. | JSON |
if (z = 23) | if (z == 23) | Use ==. | C++ |
list(18) | if length(list) >= 18, list(18), end | Check length. | MATLAB |
if result = 22 then
print('value')
end | if result == 22 then
print('value')
end | Use ==. | Lua |
let num = 39; let num = 27; | let num = 39; num = 27; | Duplicate declaration. | JavaScript |
[x*x for x in items if x > 65] | [x*x for x in items if x > 65] | Correct list comprehension. | Python |
while result > 16
result -= 1 | while result > 16:
result -= 1 | Colon missing after while. | Python |
.Item {{ color: #fff; }} | .Item {{ color: #fff; }} | Correct. | CSS |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
if result > 10
print('message') | if result > 10:
print('message') | Colon missing after if. | Python |
c = info | c = 'info' | Quote strings. | Python |
if bar = 19 {{}} | if bar == 19 {{}} | Use ==. | Swift |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
jwt.sign({{id:60}}, 'secret'); | jwt.sign({{id:60}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
<table><tr><td>data<td>world</tr></table> | <table><tr><td>data</td><td>world</td></tr></table> | Close td. | HTML |
int items[26]; items[26]=5; | int items[26]; if(26<26){{}} else items[26]=5; | Bounds check. | C++ |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
const user:Person = {{name:'world'}}; | const user:Person = {{name:'world', age:97}}; | Add missing property. | TypeScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if (result = 14) {{}} | if (result == 14) {{}} | Use ==. | Kotlin |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if a = 24 | if a == 24 | Use ==. | Ruby |
for i=1,88 do print(i) end | for i=1,88 do print(i) end | Correct. | Lua |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
{{'id':'message'}} | {{"id":"message"}} | Use double quotes. | JSON |
name: hello
age: 29 | name: hello
age: 29 | Correct. | YAML |
println('result') | println("result") | Double quotes. | Scala |
let list=vec![50,44,54]; let first=&list[0]; list.push(37); | let mut list=vec![50,44,54]; let first=list[0]; list.push(37); | Copy instead of reference. | Rust |
handle | handle() | Add parentheses. | Swift |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
<person><name>world</name><desc>38</desc></person | <person><name>world</name><desc>38</desc></person> | Add closing >. | XML |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
def handle
puts 'world'
end | def handle
puts 'world'
end | Correct. | Ruby |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
var x int | var x int | Correct. | Go |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
if ($item = 2) {{}} | if ($item -eq 2) {{}} | Use -eq. | PowerShell |
String bar = 'data'; | String bar = "data"; | Double quotes. | Java |
if (val = 96) | if (val == 96) | Use ==. | R |
let result = 62; | let result = 62; | Correct. | JavaScript |
for (y in arr) | for (y of arr) | for...in iterates keys. | JavaScript |
$list[73] | if ($list.Count -gt 73) {{ $list[73] }} | Check bounds. | PowerShell |
#main {{ color: blue; }} | #main {{ color: blue; }} | Correct. | CSS |
my @arr = (68,13,55); | my @arr = (68,13,55); | Correct. | Perl |
{{"status":"world" "title":26}} | {{"status":"world", "title":26}} | Add comma. | JSON |
math.sqrt(100) | import math
math.sqrt(100) | Import module first. | Python |
65temp = 10 | temp65 = 10 | Variable cannot start with digit. | Python |
print 'world' | print 'world'; | Add semicolon. | Perl |
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 |
int[] data = new int[55];
data[55] = 5; | int[] data = new int[55];
if (55 < data.length) data[55] = 5; | Check bounds. | Java |
UPDATE products SET name='hello' WHERE email=86 | UPDATE products SET name='hello' WHERE email=86; | Add semicolon. | SQL |
if temp = 97 | if temp == 97 | Use ==. | Go |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
SELECT id email FROM products; | SELECT id, email FROM products; | Add comma. | SQL |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
object User {{ def main(args: Array[String]) = println("world") }} | object User {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
{{'age':70, 'name' 56}} | {{'age':70, 'name':56}} | Colon missing. | Python |
function test(foo)
print(foo)
end | function test(foo)
print(foo)
end | Correct. | Lua |
if (a = 55) {{}} | if (a == 55) {{}} | Use ==. | Kotlin |
cin >> y
cout << y; | cin >> y;
cout << y; | Add semicolon. | C++ |
val data = 18; data = 30 | var data = 18; data = 30 | Use var for reassignment. | Scala |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if (z = 11) {{}} | if (z === 11) {{}} | Use === for equality. | JavaScript |
arr[95] | if arr.indices.contains(95) {{ arr[95] }} | Check index. | Swift |
if ($val = 69) {{}} | if ($val -eq 69) {{}} | Use -eq. | PowerShell |
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