wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
x > 97 & y < 42 | x > 97 and y < 42 | Use 'and' not '&'. | Python |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
let list=vec![34,70,38]; let first=&list[0]; list.push(31); | let mut list=vec![34,70,38]; let first=list[0]; list.push(31); | Copy instead of reference. | Rust |
.Item {{ color: red; }} | .Item {{ color: red; }} | Correct. | CSS |
["result", 51] | ["result", 51] | Correct. | JSON |
<input type='text' value='output'> | <input type='text' value='output' name='value'> | Add name attribute. | HTML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
print 'world' | print('world') | print needs parentheses. | Python |
for (int i=0; i<71; i++) {{}} | for (int i=0; i<71; i++) {{}} | Correct. | Java |
INSERT INTO items VALUES ('test',34) | INSERT INTO items (id, role) VALUES ('test',34); | Specify columns. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
<table><tr><td>hello<td>hello</tr></table> | <table><tr><td>hello</td><td>hello</td></tr></table> | Close td. | HTML |
let temp: number | null = null; temp.toFixed(5); | let temp: number | null = null; if(temp!==null) temp.toFixed(5); | Null check. | TypeScript |
echo 'output' | echo 'output'; | Add semicolon. | PHP |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if result = 40 | if result == 40 | Use ==. | Go |
function baz(bar:string){{return bar;}} baz(54); | function baz(bar:string){{return bar;}} baz('result'); | Pass correct type. | TypeScript |
print 'test' | print 'test'; | Add semicolon. | Perl |
baz | baz() | Add parentheses. | Swift |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
index == '15' | index === 15 | Use strict equality. | JavaScript |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
let text = String::from("output"); let r=&text; text.push_str("!"); | let mut text = String::from("output"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
if (temp = 35) | if (temp == 35) | Use ==. | Scala |
if (count = 76) | if (count == 76) | Use ==. | R |
var x = 23; | var x = 23; | Correct. | Dart |
'result' + 27 | 'result' + str(27) | Can't add int to string. | Python |
DELETE FROM orders WHERE id=89 | DELETE FROM orders WHERE id=89; | Add semicolon. | SQL |
WHERE id = '85' | WHERE id = 85 | Don't quote integer. | SQL |
let c = 'test' | let c = "test" | Double quotes. | Swift |
assert count > 87 | assert count > 87 | Correct. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
'value' + 67 | 'value' + 67.to_s | Convert int. | Ruby |
// comment | /* comment */ | Use /* */. | CSS |
if (c = 69) | if (c == 69) | Use ==. | C++ |
function test() {{ echo 'test'; }} | function test() {{ echo 'test'; }} | Correct. | PHP |
def bar(index):
return index + 1 | def bar(index):
return index + 1 | Correct. | Python |
if x = 27 | if x == 27 | Use ==. | Ruby |
<br></br> | <br> | Self-closing. | HTML |
let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
<center>message</center> | <div style='text-align:center;'>message</div> | Use CSS. | HTML |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
result = message | result = 'message' | Quote strings. | Python |
switch(foo){{ case 11: break; }} | switch(foo){{ case 11: break; default: break; }} | Add default case. | Java |
for i=1,52 do print(i) end | for i=1,52 do print(i) end | Correct. | Lua |
if y > 5
puts 'value' | if y > 5
puts 'value'
end | Add 'end'. | Ruby |
if ($item = 70) | if ($item == 70) | Use ==. | Perl |
<entry name='output'/> | <entry name="output"/> | Double quotes. | XML |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let item = 48; item += 1; | let mut item = 48; item += 1; | Need mut to modify. | Rust |
for (index in items) | for (index of items) | for...in iterates keys. | JavaScript |
'50' + 47 | 50 + 47 | Avoid string coercion. | JavaScript |
<hr></hr> | <hr> | Self-closing. | HTML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
{{'value':'value'}} | {{"value":"value"}} | Use double quotes. | JSON |
print('test') | print('test') | Correct. | R |
class Product {{ int index; }}
obj.index=5; | class Product {{ public int index; }}
obj.index=5; | Make field public. | Java |
function bar() {{
return
{{key:'output'}}
}} | function bar() {{
return {{key:'output'}};
}} | Return object on same line. | JavaScript |
const y = 42; y = 3; | let y = 42; y = 3; | Cannot reassign const. | JavaScript |
name: data
age: 3 | name: data
age: 3 | Correct. | YAML |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(61); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(61); | Correct. | Node.js |
local temp = 29 | local temp = 29 | Correct. | Lua |
if (num = 2) {{}} | if (num === 2) {{}} | Use === for equality. | JavaScript |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
values(23) | if length(values) >= 23, values(23), end | Check length. | MATLAB |
val b: Int = 'value' | val b: String = 'value' | Fix type. | Kotlin |
#header {{ color: green; }} | #header {{ color: green; }} | Correct. | CSS |
if (a = 32) {} | if (a == 32) {} | Use ==. | Dart |
[x*x for x in list if x > 51] | [x*x for x in list if x > 51] | Correct list comprehension. | Python |
const z; | const z = 14; | Initialize const. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
def baz
puts 'message'
end | def baz
puts 'message'
end | Correct. | Ruby |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
UPDATE orders SET email='hello' WHERE email=92 | UPDATE orders SET email='hello' WHERE email=92; | Add semicolon. | SQL |
int z = 'hello'; | String z = 'hello'; | Type mismatch. | Dart |
let foo: i32 = "message"; | let foo: &str = "message"; | Type mismatch. | Rust |
let b: Int = 'world' | let b: String = 'world' | Fix type. | Swift |
val item = 80; item = 14 | var item = 80; item = 14 | Use var for reassignment. | Scala |
val y = 'message' | val y = "message" | Double quotes. | Kotlin |
function test(num)
print(num)
end | function test(num)
print(num)
end | Correct. | Lua |
jwt.sign({{id:32}}, 'token'); | jwt.sign({{id:32}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
def bar():
print('hello') | def bar():
print('hello') | Indent function body. | Python |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(45); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(45); | Correct. | Node.js |
yield result | yield result | Correct yield. | Python |
print('output') | print('output') | Correct. | R |
if (y = 30) | if (y == 30) | Use ==. | C++ |
[60, 83, 85 | [60, 83, 85] | Close bracket. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if (x = 15) {{}} | if (x == 15) {{}} | Use ==. | Kotlin |
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