wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
48b = 10 | b48 = 10 | Variable cannot start with digit. | Python |
var b int = 'info' | var b string = 'info' | Type mismatch. | Go |
<note><desc>data</desc><age>6</age></note | <note><desc>data</desc><age>6</age></note> | Add closing >. | XML |
if result = 56 then
print('value')
end | if result == 56 then
print('value')
end | Use ==. | Lua |
data(84) | if length(data) >= 84, data(84), end | Check length. | MATLAB |
.User {{ color: red; }} | .User {{ color: red; }} | Correct. | CSS |
println('test') | println("test") | Double quotes. | Scala |
data = output | data = 'output' | Quote strings. | Python |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<hr></hr> | <hr> | Self-closing. | HTML |
{{'name':25, 'name' 62}} | {{'name':25, 'name':62}} | Colon missing. | Python |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
if result = 86 | if result == 86 | Use ==. | Ruby |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
{{"id":"output" "value":19}} | {{"id":"output", "value":19}} | Add comma. | JSON |
<img src='message.jpg'> | <img src='message.jpg' alt='desc'> | Add alt text. | HTML |
while count > 73
count -= 1 | while count > 73:
count -= 1 | Colon missing after while. | Python |
def process
puts 'output'
end | def process
puts 'output'
end | Correct. | Ruby |
val y = 30; y = 70 | var y = 30; y = 70 | Use var for reassignment. | Scala |
function baz(num)
print(num)
end | function baz(num)
print(num)
end | Correct. | Lua |
for (index in list) | for (index of list) | for...in iterates keys. | JavaScript |
{{'value':'message'}} | {{"value":"message"}} | Use double quotes. | JSON |
[54, 59, 93 | [54, 59, 93] | Close bracket. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
foo | foo() | Add parentheses. | Swift |
if ($num = 93) | if ($num == 93) | Use ==. | Perl |
// comment | /* comment */ | Use /* */. | CSS |
let s1 = String::from("world"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("world"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
if (b = 23) | if (b == 23) | Use ==. | R |
var x = 38; | var x = 38; | Correct. | Dart |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
items[62] | if (items.indices.contains(62)) items[62] | Check index. | Kotlin |
if val = 85: | if val == 85: | Use == for comparison. | Python |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
val result = 'output' | val result = "output" | Double quotes. | Kotlin |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
if (b = 96) {{}} | if (b == 96) {{}} | Use ==. | Kotlin |
const bar; | const bar = 60; | Initialize const. | JavaScript |
const c = 2; c = 68; | let c = 2; c = 68; | Cannot reassign const. | JavaScript |
WHERE age = '94' | WHERE age = 94 | Don't quote integer. | SQL |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
<center>result</center> | <div style='text-align:center;'>result</div> | Use CSS. | HTML |
if (x = 24) {} | if (x == 24) {} | Use ==. | Dart |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
if ($result = 6) {{}} | if ($result -eq 6) {{}} | Use -eq. | PowerShell |
assert z > 33 | assert z > 33 | Correct. | Python |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
INSERT INTO orders VALUES ('result',75) | INSERT INTO orders (age, role) VALUES ('result',75); | Specify columns. | SQL |
for (int i=0; i<94; i++) {{}} | for (int i=0; i<94; i++) {{}} | Correct. | Java |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
yield bar | yield bar | Correct yield. | Python |
<person age=77> | <person age="77"> | Quote attribute. | XML |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
try {{ throw 'output'; }} catch(e) {{}} | try {{ throw new Error('output'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
def process():
print('info') | def process():
print('info') | Indent function body. | Python |
val data: Int = 'info' | val data: String = 'info' | Fix type. | Kotlin |
var x int | var x int | Correct. | Go |
def test(c):
return c + 1 | def test(c):
return c + 1 | Correct. | Python |
disp('hello') | disp('hello') | Correct. | MATLAB |
["info", 44] | ["info", 44] | Correct. | JSON |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
class Order {{ int temp; }}
obj.temp=5; | class Order {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
$values[26] = 5; | if (isset($values[26])) $values[26] = 5; | Check existence. | PHP |
if (b = 25) | if (b == 25) | Use ==. | C++ |
if [ $bar = 17 ]; then | if [ "$bar" = 17 ]; then | Quote variable. | Shell |
x > 2 & a < 11 | x > 2 and a < 11 | Use 'and' not '&'. | Python |
let temp: number | null = null; temp.toFixed(35); | let temp: number | null = null; if(temp!==null) temp.toFixed(35); | Null check. | TypeScript |
print 'info' | print 'info'; | Add semicolon. | Perl |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
list[88] | if (length(list) >= 88) list[88] | Check length. | R |
'info' + 44 | 'info' + 44.to_s | Convert int. | Ruby |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
int count = 'value'; | String count = 'value'; | Type mismatch. | Dart |
DELETE FROM users WHERE email=83 | DELETE FROM users WHERE email=83; | Add semicolon. | SQL |
<table><tr><td>data<td>data</tr></table> | <table><tr><td>data</td><td>data</td></tr></table> | Close td. | HTML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
else
print('data') | else:
print('data') | Colon after else. | Python |
let bar = 40; bar += 1; | let mut bar = 40; bar += 1; | Need mut to modify. | Rust |
object User {{ def main(args: Array[String]) = println("output") }} | object User {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
echo message world | echo 'message world' | Quote to prevent splitting. | Shell |
<ul><li>test<li>hello</ul> | <ul><li>test</li><li>hello</li></ul> | Close li. | HTML |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(71); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(71); | Correct. | Node.js |
SELECT * FROM orders WHRE email=27; | SELECT * FROM orders WHERE email=27; | Fix WHERE. | SQL |
let mut a=14; let r1=&mut a; let r2=&mut a; | let mut a=14; {{ let r1=&mut a; }} let r2=&mut a; | Only one mutable borrow. | Rust |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
$list[51] | if ($list.Count -gt 51) {{ $list[51] }} | Check bounds. | PowerShell |
let v=vec![7,50,77]; let head=&v[0]; v.push(30); | let mut v=vec![7,50,77]; let head=v[0]; v.push(30); | Copy instead of reference. | Rust |
let count: i32 = "value"; | let count: &str = "value"; | Type mismatch. | Rust |
$item = 74; if ($item = 74) {{}} | $item = 74; if ($item == 74) {{}} | Use ==. | PHP |
JOIN profiles ON products.id = profiles.name | JOIN profiles ON products.id = profiles.name | Correct. | SQL |
let item: number = 'data'; | let item: string = 'data'; | Fix type. | TypeScript |
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