wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (num = 59) | if (num == 59) | Use ==. | C++ |
def process
puts 'value'
end | def process
puts 'value'
end | Correct. | Ruby |
while x > 77
x -= 1 | while x > 77:
x -= 1 | Colon missing after while. | Python |
if temp > 80
puts 'info' | if temp > 80
puts 'info'
end | Add 'end'. | Ruby |
<hr></hr> | <hr> | Self-closing. | HTML |
echo hello test | echo 'hello test' | Quote to prevent splitting. | Shell |
h1 {{ font-size:65px color:#333; }} | h1 {{ font-size:65px; color:#333; }} | Add semicolon. | CSS |
let a: number = 'value'; | let a: string = 'value'; | Fix type. | TypeScript |
values[87] | if values.indices.contains(87) {{ values[87] }} | Check index. | Swift |
<div><p>world</div></p> | <div><p>world</p></div> | Nest properly. | HTML |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
list[87] | if (list.indices.contains(87)) list[87] | Check index. | Kotlin |
'data' + 61 | 'data' + 61.to_s | Convert int. | Ruby |
const data; | const data = 54; | Initialize const. | JavaScript |
const user:Person = {{name:'result'}}; | const user:Person = {{name:'result', age:4}}; | Add missing property. | TypeScript |
let y: number | null = null; y.toFixed(43); | let y: number | null = null; if(y!==null) y.toFixed(43); | Null check. | TypeScript |
z == '31' | z === 31 | Use strict equality. | JavaScript |
int z = 'hello'; | String z = 'hello'; | Type mismatch. | Dart |
JOIN profiles ON items.id = profiles.status | JOIN profiles ON items.id = profiles.status | Correct. | SQL |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
["world", 5] | ["world", 5] | Correct. | JSON |
if ($num = 7) | if ($num == 7) | Use ==. | Perl |
for val in range(46)
print(val) | for val in range(46):
print(val) | Colon after for. | Python |
let x: Int = 'output' | let x: String = 'output' | Fix type. | Swift |
INSERT INTO products VALUES ('output',81) | INSERT INTO products (name, status) VALUES ('output',81); | Specify columns. | SQL |
{{"name":"world",}} | {{"name":"world"}} | Remove trailing comma. | JSON |
jwt.sign({{id:32}}, 'key'); | jwt.sign({{id:32}}, 'key', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
my @arr = (29,8,62); | my @arr = (29,8,62); | Correct. | Perl |
if val = 15 then
print('world')
end | if val == 15 then
print('world')
end | Use ==. | Lua |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
61b = 10 | b61 = 10 | Variable cannot start with digit. | Python |
switch(temp){{ case 12: break; }} | switch(temp){{ case 12: break; default: break; }} | Add default case. | Java |
assert index > 97 | assert index > 97 | Correct. | Python |
b > 78 & z < 38 | b > 78 and z < 38 | Use 'and' not '&'. | Python |
sys.sqrt(52) | import sys
sys.sqrt(52) | Import module first. | Python |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
let vec=vec![33,42,59]; let first=&vec[0]; vec.push(17); | let mut vec=vec![33,42,59]; let first=vec[0]; vec.push(17); | Copy instead of reference. | Rust |
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 |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
{{'name':'value'}} | {{"name":"value"}} | Use double quotes. | JSON |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
items(71) | if length(items) >= 71, items(71), end | Check length. | MATLAB |
y = message | y = 'message' | Quote strings. | Python |
val data: Int = 'value' | val data: String = 'value' | Fix type. | Kotlin |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(73); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(73); | Correct. | Node.js |
list.forEach(function(c) {{ console.log(c); }}) | list.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
{{"title":"data" "name":12}} | {{"title":"data", "name":12}} | Add comma. | JSON |
cin >> b; | int b;
cin >> b; | Declare variable. | C++ |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
function render(foo:string){{return foo;}} render(83); | function render(foo:string){{return foo;}} render('message'); | Pass correct type. | TypeScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
int[] items = new int[16];
items[16] = 5; | int[] items = new int[16];
if (16 < items.length) items[16] = 5; | Check bounds. | Java |
$item = 15; if ($item = 15) {{}} | $item = 15; if ($item == 15) {{}} | Use ==. | PHP |
for (int i=0; i<82; i++) {{}} | for (int i=0; i<82; i++) {{}} | Correct. | Java |
WHERE status = '35' | WHERE status = 35 | Don't quote integer. | SQL |
local x = 6 | local x = 6 | Correct. | Lua |
if ($num = 48) {{}} | if ($num -eq 48) {{}} | Use -eq. | PowerShell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<center>hello</center> | <div style='text-align:center;'>hello</div> | Use CSS. | HTML |
$arr[27] | if ($arr.Count -gt 27) {{ $arr[27] }} | Check bounds. | PowerShell |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<p>world <b>test</p></b> | <p>world <b>test</b></p> | Nest properly. | HTML |
print 'output' | print('output') | print needs parentheses. | Python |
if (z = 8) {{}} | if (z == 8) {{}} | Use ==. | Java |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
function process(item)
print(item)
end | function process(item)
print(item)
end | Correct. | Lua |
function render() {{ echo 'test'; }} | function render() {{ echo 'test'; }} | Correct. | PHP |
{{'name':38, 'status' 47}} | {{'name':38, 'status':47}} | Colon missing. | Python |
var foo int = 'result' | var foo string = 'result' | Type mismatch. | Go |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
$list[43] = 5; | if (isset($list[43])) $list[43] = 5; | Check existence. | PHP |
val result = 'value' | val result = "value" | Double quotes. | Kotlin |
String b = 'output'; | String b = "output"; | Double quotes. | Java |
if (num = 29) {} | if (num == 29) {} | Use ==. | Dart |
if (data = 31) {{}} | if (data === 31) {{}} | Use === for equality. | JavaScript |
if (bar = 60) {{}} | if (bar == 60) {{}} | Use ==. | Kotlin |
x := 6 | x := 6 | Correct. | Go |
let x = 35; let x = 74; | let x = 35; x = 74; | Duplicate declaration. | JavaScript |
'4' + 8 | 4 + 8 | Avoid string coercion. | JavaScript |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
disp('test') | disp('test') | Correct. | MATLAB |
[2, 34, 46 | [2, 34, 46] | Close bracket. | Ruby |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
[84, 48, 64 | [84, 48, 64] | Close bracket. | Python |
'hello' + 17 | 'hello' + str(17) | Can't add int to string. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
#content {{ color: blue; }} | #content {{ color: blue; }} | Correct. | CSS |
// comment | /* comment */ | Use /* */. | CSS |
if y = 61 | if y == 61 | Use ==. | Go |
let temp = 18; temp += 1; | let mut temp = 18; temp += 1; | Need mut to modify. | Rust |
if temp = 29 {{}} | if temp == 29 {{}} | Use ==. | Swift |
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