Avoid use of
== and != JS-0050
Anti-pattern
Minor
8 months ago
—
3 years old
Expected '===' and instead saw '=='
1515 }
1516 if (ilce !== null && ilce !== undefined) {
1517 var ilceArray = ilceler.features.filter(
1518 (item) => item.properties.Id == ilce1519 );
1520 locationCondition = Tutorial.sequelize.where(
1521 Tutorial.sequelize.fn(Expected '===' and instead saw '=='
1498
1499 if (il !== null && il !== undefined) {
1500 var ilArray = illergeojson.features.filter(
1501 (item) => item.properties.name.toLowerCase() == il.toLowerCase()1502 );
1503 locationCondition = Tutorial.sequelize.where(
1504 Tutorial.sequelize.fn(Expected '===' and instead saw '=='
864 : null,
865
866 //published will be true if the userStatus is 'user'. if not, it can be false or true.
867 userStatus == "user" 868 ? { published: true }
869 : { published: { [Op.or]: [true, false] } }
870 ),Expected '===' and instead saw '=='
778 }
779 : null,
780 //published will be true if the userStatus is 'user'. if not, it can be false or true.
781 userStatus == "user" 782 ? { published: true }
783 : { published: { [Op.or]: [true, false] } },
784 ]Expected '===' and instead saw '=='
579 : null,
580
581 //published will be true if the userStatus is 'user'. if not, it can be false or true.
582 userStatus == "user" 583 ? { published: true }
584 : { published: { [Op.or]: [true, false] } }
585 ),
Description
It is considered good practice to use the type-safe equality operators === and !== instead of their regular counterparts == and !=.
The strict equality operators (=== and !==) use the strict equality comparison algorithm to compare two operands.
- If the operands are of different types, return
false. - If both operands are objects, return
trueonly if they refer to the same object. - If both operands are
nullor both operands areundefined, returntrue. - If either operand is
NaN, returnfalse. - Otherwise, compare the two operand's values:
- Numbers must have the same numeric values.
+0and-0are considered to be the same value. - Strings must have the same characters in the same order.
- Booleans must be both
trueor bothfalse.
- Numbers must have the same numeric values.
The most notable difference between this operator and the equality (==) operator is that if the operands are of different types, the == operator attempts to convert them to the same type before comparing.
Bad Practice
a == b
foo == true
bananas != 1
value == undefined
typeof foo == 'undefined'
'hello' != 'world'
0 == 0
true == true
foo == null
Recommended
a === b
foo === true
bananas !== 1
value === undefined
typeof foo === 'undefined'
'hello' !== 'world'
0 === 0
true === true
foo === null