Avoid use of
== and != JS-0050
Anti-pattern
Minor
a year ago
—
a year old
Expected '===' and instead saw '=='.
258
259
260function doAdjustment(id, title, amount, form, type){
261 if ((id==null) | (id ===""))return;262 db.collection(type).doc(id).set({
263 id: id,
264 title: title,Expected '===' and instead saw '=='.
96
97 $('select#ptbtype').change(function(){
98 var selectedtype = $(this).children("option:selected").val();
99 if(selectedtype == 'liability'){100 $('.hide-for-liab').slideDown();
101 }else{
102 $('.hide-for-liab').slideUp();Expected '===' and instead saw '=='.
87
88 $('select#ptbtype').change(function(){
89 var selectedtype = $(this).children("option:selected").val();
90 if(selectedtype == 'asset'){ 91 $('.hide-for-ass').slideDown();
92 }else{
93 $('.hide-for-ass').slideUp();Expected '===' and instead saw '=='.
78
79 $('select#ptbtype').change(function(){
80 var selectedtype = $(this).children("option:selected").val();
81 if(selectedtype == 'expense'){ 82 $('.hide-for-exp').slideDown();
83 }else{
84 $('.hide-for-exp').slideUp();Expected '===' and instead saw '=='.
54 $('.adjhide').hide();
55 $('.inad-area').slideDown();
56 }
57 else if(selectedAdj == 'baddebt'){ 58 $('.adjhide').hide();
59 $('.baddebt-area').slideDown();
60 }
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