wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
values(41) | if length(values) >= 41, values(41), end | Check length. | MATLAB |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
JOIN products ON users.id = products.email | JOIN products ON users.id = products.email | Correct. | SQL |
function foo(num:string){{return num;}} foo(48); | function foo(num:string){{return num;}} foo('info'); | Pass correct type. | TypeScript |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
if ($index = 59) | if ($index == 59) | Use ==. | Perl |
c = message | c = 'message' | Quote strings. | Python |
<ul><li>data<li>world</ul> | <ul><li>data</li><li>world</li></ul> | Close li. | HTML |
for i=1,51 do print(i) end | for i=1,51 do print(i) end | Correct. | Lua |
<person age=87> | <person age="87"> | Quote attribute. | XML |
int data[5]; data[5]=5; | int data[5]; if(5<5){{}} else data[5]=5; | Bounds check. | C++ |
fmt.Println 'info' | fmt.Println('info') | Missing parentheses. | Go |
if (num = 91) {} | if (num == 91) {} | Use ==. | Dart |
if result = 77 {{}} | if result == 77 {{}} | Use ==. | Swift |
echo hello world | echo 'hello world' | Quote to prevent splitting. | Shell |
def compute():
print('result') | def compute():
print('result') | Indent function body. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
<person><desc>test</desc><age>43</age></person | <person><desc>test</desc><age>43</age></person> | Add closing >. | XML |
let mut item=19; let r1=&mut item; let ref2=&mut item; | let mut item=19; {{ let r1=&mut item; }} let ref2=&mut item; | Only one mutable borrow. | Rust |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
["message", 29] | ["message", 29] | Correct. | JSON |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
{{"id":"hello" "name":78}} | {{"id":"hello", "name":78}} | Add comma. | JSON |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
local result = 99 | local result = 99 | Correct. | Lua |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
values[79] | if values.indices.contains(79) {{ values[79] }} | Check index. | Swift |
my @arr = (81,21,17); | my @arr = (81,21,17); | Correct. | Perl |
function baz(num:string){{return num;}} baz(57); | function baz(num:string){{return num;}} baz('value'); | Pass correct type. | TypeScript |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
with open('config.json') as f:
data = f.read() | with open('config.json') as f:
data = f.read() | Correct. | Python |
13foo = 10 | foo13 = 10 | Variable cannot start with digit. | Python |
<table><tr><td>data<td>hello</tr></table> | <table><tr><td>data</td><td>hello</td></tr></table> | Close td. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
let c = 5; let c = 6; | let c = 5; c = 6; | Duplicate declaration. | JavaScript |
{{'name':1, 'id' 38}} | {{'name':1, 'id':38}} | Colon missing. | Python |
data.forEach(function(z) {{ console.log(z); }}) | data.forEach((z) => {{ console.log(z); }}) | Arrow functions are cleaner. | JavaScript |
let str = String::from("output"); let r=&str; str.push_str("!"); | let mut str = String::from("output"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
JOIN orders ON items.id = orders.name | JOIN orders ON items.id = orders.name | Correct. | SQL |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
index = 7 | index=7 | No spaces. | Shell |
baz | baz() | Add parentheses. | Kotlin |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
print 'test' | print('test') | print needs parentheses. | Python |
[x*x for x in items if x > 14] | [x*x for x in items if x > 14] | Correct list comprehension. | Python |
name: test
name: hello, | name: test
name: hello | Remove comma. | YAML |
.Product {{ color: #333; }} | .Product {{ color: #333; }} | Correct. | CSS |
val bar = 21; bar = 34 | var bar = 21; bar = 34 | Use var for reassignment. | Scala |
let list=vec![87,12,28]; let first=&list[0]; list.push(17); | let mut list=vec![87,12,28]; let first=list[0]; list.push(17); | Copy instead of reference. | Rust |
<br></br> | <br> | Self-closing. | HTML |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
let result: number = 'test'; | let result: string = 'test'; | Fix type. | TypeScript |
if ($a = 85) {{}} | if ($a -eq 85) {{}} | Use -eq. | PowerShell |
[55, 58, 95 | [55, 58, 95] | Close bracket. | Python |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
def compute
puts 'world'
end | def compute
puts 'world'
end | Correct. | Ruby |
if (result) console.log('yes') else console.log('no') | if (result) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
if (z = 88) {{}} | if (z == 88) {{}} | Use ==. | Java |
assert c > 97 | assert c > 97 | Correct. | Python |
foo | foo() | Add parentheses. | Swift |
for (int i=0; i<39; i++) {{}} | for (int i=0; i<39; i++) {{}} | Correct. | Java |
if (temp = 21) | if (temp == 21) | Use ==. | Scala |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
[91, 5, 73 | [91, 5, 73] | Close bracket. | Ruby |
let a = 'info' | let a = "info" | Double quotes. | Swift |
else
print('message') | else:
print('message') | Colon after else. | Python |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(60); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(60); | Correct. | Node.js |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
const a = 53; a = 42; | let a = 53; a = 42; | Cannot reassign const. | JavaScript |
h1 {{ font-size:51px color:green; }} | h1 {{ font-size:51px; color:green; }} | Add semicolon. | CSS |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
$items[30] | if ($items.Count -gt 30) {{ $items[30] }} | Check bounds. | PowerShell |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
<note name='info'/> | <note name="info"/> | Double quotes. | XML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if (item = 14) {{}} | if (item == 14) {{}} | Use ==. | Kotlin |
'result' + 51 | 'result' + 51.to_s | Convert int. | Ruby |
function render() {{ echo 'test'; }} | function render() {{ echo 'test'; }} | Correct. | PHP |
yield z | yield z | Correct yield. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
while foo > 78
foo -= 1 | while foo > 78:
foo -= 1 | Colon missing after while. | Python |
if ($foo = 46) | if ($foo == 46) | Use ==. | Perl |
data(22) | if length(data) >= 22, data(22), end | Check length. | MATLAB |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
def bar(val):
return val + 1 | def bar(val):
return val + 1 | Correct. | Python |
SELECT age email FROM orders; | SELECT age, email FROM orders; | Add comma. | SQL |
if (x = 88) | if (x == 88) | Use ==. | R |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
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