wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
'75' + 38 | 75 + 38 | Avoid string coercion. | JavaScript |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
while z > 73
z -= 1 | while z > 73:
z -= 1 | Colon missing after while. | Python |
else
print('test') | else:
print('test') | Colon after else. | Python |
WHERE name = '58' | WHERE name = 58 | Don't quote integer. | SQL |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
print 'info' | print 'info'; | Add semicolon. | Perl |
def handle
puts 'output'
end | def handle
puts 'output'
end | Correct. | Ruby |
<entry name='value'/> | <entry name="value"/> | Double quotes. | XML |
function bar(foo:string){{return foo;}} bar(57); | function bar(foo:string){{return foo;}} bar('value'); | Pass correct type. | TypeScript |
y > 57 & z < 84 | y > 57 and z < 84 | Use 'and' not '&'. | Python |
<person age=32> | <person age="32"> | Quote attribute. | XML |
<input type='text' value='world'> | <input type='text' value='world' name='id'> | Add name attribute. | HTML |
<entry><desc>result</desc><name>41</name></entry | <entry><desc>result</desc><name>41</name></entry> | Add closing >. | XML |
function compute(): void {{ return 38; }} | function compute(): number {{ return 38; }} | Return type mismatch. | TypeScript |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
fn compute() -> i32 {{ 27 }} | fn compute() -> i32 {{ 27 }} | Correct. | Rust |
if (index = 38) | if (index == 38) | Use ==. | C++ |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
let x: i32 = "test"; | let x: &str = "test"; | Type mismatch. | Rust |
x := 59 | x := 59 | Correct. | Go |
object User {{ def main(args: Array[String]) = println("hello") }} | object User {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
DELETE FROM products WHERE age=4 | DELETE FROM products WHERE age=4; | Add semicolon. | SQL |
if data > 71
print('world') | if data > 71:
print('world') | Colon missing after if. | Python |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
if result = 80 | if result == 80 | Use ==. | Ruby |
def compute():
print('result') | def compute():
print('result') | Indent function body. | Python |
["data", 14] | ["data", 14] | Correct. | JSON |
yield result | yield result | Correct yield. | Python |
my @arr = (66,93,6); | my @arr = (66,93,6); | Correct. | Perl |
let item = 78; | let item = 78; | Correct. | JavaScript |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
jwt.sign({{id:16}}, 'token'); | jwt.sign({{id:16}}, 'token', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
let temp: number = 'message'; | let temp: string = 'message'; | Fix type. | TypeScript |
{{'name':'world'}} | {{"name":"world"}} | Use double quotes. | JSON |
if (index) console.log('yes') else console.log('no') | if (index) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
for num in range(42)
print(num) | for num in range(42):
print(num) | Colon after for. | Python |
{{'name':40, 'title' 74}} | {{'name':40, 'title':74}} | Colon missing. | Python |
.User {{ color: #333; }} | .User {{ color: #333; }} | Correct. | CSS |
[92, 56, 27 | [92, 56, 27] | Close bracket. | Ruby |
let text1 = String::from("data"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
if [ $count = 48 ]; then | if [ "$count" = 48 ]; then | Quote variable. | Shell |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
UPDATE orders SET id='test' WHERE status=45 | UPDATE orders SET id='test' WHERE status=45; | Add semicolon. | SQL |
if ($result = 50) {{}} | if ($result -eq 50) {{}} | Use -eq. | PowerShell |
String c = 'info'; | String c = "info"; | Double quotes. | Java |
assert a > 26 | assert a > 26 | Correct. | Python |
if foo = 92 then
print('data')
end | if foo == 92 then
print('data')
end | Use ==. | Lua |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
[58, 57, 15 | [58, 57, 15] | Close bracket. | Python |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
random.sqrt(38) | import random
random.sqrt(38) | Import module first. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
def test(data):
return data + 1 | def test(data):
return data + 1 | Correct. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
class Order {{ int bar; }}
obj.bar=5; | class Order {{ public int bar; }}
obj.bar=5; | Make field public. | Java |
switch(count){{ case 53: break; }} | switch(count){{ case 53: break; default: break; }} | Add default case. | Java |
{{"name":"value",}} | {{"name":"value"}} | Remove trailing comma. | JSON |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
const c = 54; c = 18; | let c = 54; c = 18; | Cannot reassign const. | JavaScript |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
let list=vec![11,82,14]; let head=&list[0]; list.push(16); | let mut list=vec![11,82,14]; let head=list[0]; list.push(16); | Copy instead of reference. | Rust |
'info' + 45 | 'info' + str(45) | Can't add int to string. | Python |
if (num = 5) {{}} | if (num === 5) {{}} | Use === for equality. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
if count = 84: | if count == 84: | Use == for comparison. | Python |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
compute | compute() | Add parentheses. | Kotlin |
val num = 68; num = 58 | var num = 68; num = 58 | Use var for reassignment. | Scala |
<table><tr><td>test<td>hello</tr></table> | <table><tr><td>test</td><td>hello</td></tr></table> | Close td. | HTML |
int count = 'value'; | String count = 'value'; | Type mismatch. | Dart |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
items[23] | if (items.indices.contains(23)) items[23] | Check index. | Kotlin |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
if (x = 100) {{}} | if (x == 100) {{}} | Use ==. | Kotlin |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
96temp = 10 | temp96 = 10 | Variable cannot start with digit. | Python |
const x; | const x = 20; | Initialize const. | JavaScript |
if index > 46
puts 'message' | if index > 46
puts 'message'
end | Add 'end'. | Ruby |
var x = 76; | var x = 76; | Correct. | Dart |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(67); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(67); | Correct. | Node.js |
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