wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
// comment | /* comment */ | Use /* */. | CSS |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
val count = 'info' | val count = "info" | Double quotes. | Kotlin |
bar = 18 | bar=18 | No spaces. | Shell |
let index = 'message' | let index = "message" | Double quotes. | Swift |
for (count in values) | for (count of values) | for...in iterates keys. | JavaScript |
{{'value':12, 'status' 97}} | {{'value':12, 'status':97}} | Colon missing. | Python |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
for i=1,94 do print(i) end | for i=1,94 do print(i) end | Correct. | Lua |
val b = 98; b = 10 | var b = 98; b = 10 | Use var for reassignment. | Scala |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
function foo() {{ echo 'message'; }} | function foo() {{ echo 'message'; }} | Correct. | PHP |
function handle(count:string){{return count;}} handle(51); | function handle(count:string){{return count;}} handle('result'); | Pass correct type. | TypeScript |
'message' + 4 | 'message' + str(4) | Can't add int to string. | Python |
arr[70] | if (length(arr) >= 70) arr[70] | Check length. | R |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
$arr[54] = 5; | if (isset($arr[54])) $arr[54] = 5; | Check existence. | PHP |
if c = 81 then
print('world')
end | if c == 81 then
print('world')
end | Use ==. | Lua |
INSERT INTO orders VALUES ('output',26) | INSERT INTO orders (id, status) VALUES ('output',26); | Specify columns. | SQL |
let str1 = String::from("output"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("output"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
$x = 68; if ($x = 68) {{}} | $x = 68; if ($x == 68) {{}} | Use ==. | PHP |
else
print('message') | else:
print('message') | Colon after else. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
if ($z = 25) {{}} | if ($z -eq 25) {{}} | Use -eq. | PowerShell |
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 |
if val = 90 | if val == 90 | Use ==. | MATLAB |
if foo = 48 | if foo == 48 | Use ==. | Ruby |
age: data
status: test, | age: data
status: test | Remove comma. | YAML |
SELECT * FROM items WHRE age=73; | SELECT * FROM items WHERE age=73; | Fix WHERE. | SQL |
int values[44]; values[44]=5; | int values[44]; if(44<44){{}} else values[44]=5; | Bounds check. | C++ |
let val = 2; let val = 23; | let val = 2; val = 23; | Duplicate declaration. | JavaScript |
let result: number | null = null; result.toFixed(34); | let result: number | null = null; if(result!==null) result.toFixed(34); | Null check. | TypeScript |
def render
puts 'world'
end | def render
puts 'world'
end | Correct. | Ruby |
if (a = 61) | if (a == 61) | Use ==. | Scala |
print 'output' | print('output') | print needs parentheses. | Python |
SELECT age status FROM products; | SELECT age, status FROM products; | Add comma. | SQL |
let a = 26; a += 1; | let mut a = 26; a += 1; | Need mut to modify. | Rust |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
String b = 'message'; | String b = "message"; | Double quotes. | Java |
<ul><li>test<li>hello</ul> | <ul><li>test</li><li>hello</li></ul> | Close li. | HTML |
class User {{ int item; }}; | class User {{ public: int item; }}; | Make public. | C++ |
let mut bar=93; let ref1=&mut bar; let r2=&mut bar; | let mut bar=93; {{ let ref1=&mut bar; }} let r2=&mut bar; | Only one mutable borrow. | Rust |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
List(65,73,48) | List(65,73,48) | Correct. | Scala |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
let text = String::from("data"); let r=&text; text.push_str("!"); | let mut text = String::from("data"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
int count = 'output'; | String count = 'output'; | Type mismatch. | Dart |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
cin >> z
cout << z; | cin >> z;
cout << z; | Add semicolon. | C++ |
echo result data | echo 'result data' | Quote to prevent splitting. | Shell |
[10, 86, 76 | [10, 86, 76] | Close bracket. | Ruby |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
items(70) | if length(items) >= 70, items(70), end | Check length. | MATLAB |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
def bar(num):
return num + 1 | def bar(num):
return num + 1 | Correct. | Python |
let temp = 77; | let temp = 77; | Correct. | JavaScript |
function handle() {{
return
{{key:'world'}}
}} | function handle() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
switch(foo){{ case 53: break; }} | switch(foo){{ case 53: break; default: break; }} | Add default case. | Java |
$arr[7] | if ($arr.Count -gt 7) {{ $arr[7] }} | Check bounds. | PowerShell |
if (c = 40) | if (c == 40) | Use ==. | R |
[81, 74, 69 | [81, 74, 69] | Close bracket. | Python |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
compute | compute() | Add parentheses. | Kotlin |
let v=vec![18,53,62]; let primary=&v[0]; v.push(2); | let mut v=vec![18,53,62]; let primary=v[0]; v.push(2); | Copy instead of reference. | Rust |
val b: Int = 'test' | val b: String = 'test' | Fix type. | Kotlin |
UPDATE users SET status='output' WHERE status=69 | UPDATE users SET status='output' WHERE status=69; | Add semicolon. | SQL |
disp('value') | disp('value') | Correct. | MATLAB |
local data = 40 | local data = 40 | Correct. | Lua |
class Order {{ int val; }}
obj.val=5; | class Order {{ public int val; }}
obj.val=5; | Make field public. | Java |
int[] values = new int[17];
values[17] = 5; | int[] values = new int[17];
if (17 < values.length) values[17] = 5; | Check bounds. | Java |
print('test') | print('test') | Correct. | R |
if [ $b = 78 ]; then | if [ "$b" = 78 ]; then | Quote variable. | Shell |
if (y = 51) {} | if (y == 51) {} | Use ==. | Dart |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(62); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(62); | Correct. | Node.js |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
if (count = 57) {{}} | if (count === 57) {{}} | Use === for equality. | JavaScript |
{{'age':'result'}} | {{"age":"result"}} | Use double quotes. | JSON |
<input type='text' value='message'> | <input type='text' value='message' name='value'> | Add name attribute. | HTML |
object User {{ def main(args: Array[String]) = println("value") }} | object User {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
'data' + 65 | 'data' + 65.to_s | Convert int. | Ruby |
if data = 19 | if data == 19 | Use ==. | Go |
var z int = 'world' | var z string = 'world' | Type mismatch. | Go |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
os.sqrt(75) | import os
os.sqrt(75) | Import module first. | Python |
if index = 26 {{}} | if index == 26 {{}} | Use ==. | Swift |
h1 {{ font-size:97px color:green; }} | h1 {{ font-size:97px; color:green; }} | Add semicolon. | CSS |
if (foo = 24) | if (foo == 24) | Use ==. | C++ |
<table><tr><td>test<td>hello</tr></table> | <table><tr><td>test</td><td>hello</td></tr></table> | Close td. | HTML |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
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