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このルールを試す ID: javascript-code-style/strict-equals
Language: JavaScript
Severity: Notice
Category: Best Practices
Description In JavaScript, == and != comparisons do type coercion, which can be confusing and may introduce potential errors. Use the type-safe equality operators === and !== instead.
Non-Compliant Code Examples a == b ;
a != b ;
typeof a == 'number' ;
typeof a == 'number' ;
'string' != typeof a ;
true == true ;
2 == 3 ;
2 == 3 ;
'hello' != 'world' ;
'hello' != 'world' ;
a == null ;
a == null ;
null != a ;
true == 1 ;
0 != '1' ;
'wee' == /wee/ ;
typeof a == 'number' ;
'string' != typeof a ;
'hello' != 'world' ;
2 == 3 ;
true == true ;
true == null ;
true != null ;
null == null ;
null != null ;
a
==
b ;
( a ) == b ;
( a ) != b ;
a == ( b );
a != ( b );
( a ) == ( b );
( a == b ) == ( c );
( a != b ) != ( c );
a == b ;
a != b ;
( a + b ) == c ;
( a + b ) != c ;
(( 1 ) ) == ( 2 );
Compliant Code Examples a === b
a !== b
a === b
a !== null
a === null
a !== null
null === null
null !== null
// https://github.com/eslint/eslint/issues/8020
foo === /abc/u
// bigint
foo === 1 n
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