JS-0050 · Avoid use of `==` and `!=`

Avoid use of == and != JS-0050

Anti-pattern

Minor

15 days ago — 3 years old

Expected '===' and instead saw '=='

112            if (level.id != this.selectedLevel) return "";
113            if (level.id == this.selectedLevel && level.mode == buttonMode) {
114                if (buttonMode == 0) return "blue white--text";
115                if (buttonMode == 1) return "red white--text";116                else return "green white--text";
117            }
118            return "";

Expected '===' and instead saw '=='

src/components/LayerToolbar.vue

111        getButtonColor(level, buttonMode) {
112            if (level.id != this.selectedLevel) return "";
113            if (level.id == this.selectedLevel && level.mode == buttonMode) {
114                if (buttonMode == 0) return "blue white--text";115                if (buttonMode == 1) return "red white--text";
116                else return "green white--text";
117            }

Expected '===' and instead saw '=='

src/components/LayerToolbar.vue

110
111        getButtonColor(level, buttonMode) {
112            if (level.id != this.selectedLevel) return "";
113            if (level.id == this.selectedLevel && level.mode == buttonMode) {114                if (buttonMode == 0) return "blue white--text";
115                if (buttonMode == 1) return "red white--text";
116                else return "green white--text";

Expected '===' and instead saw '=='

src/components/LayerToolbar.vue

110
111        getButtonColor(level, buttonMode) {
112            if (level.id != this.selectedLevel) return "";
113            if (level.id == this.selectedLevel && level.mode == buttonMode) {114                if (buttonMode == 0) return "blue white--text";
115                if (buttonMode == 1) return "red white--text";
116                else return "green white--text";

Expected '!==' and instead saw '!='

src/components/LayerToolbar.vue

109        },
110
111        getButtonColor(level, buttonMode) {
112            if (level.id != this.selectedLevel) return "";113            if (level.id == this.selectedLevel && level.mode == buttonMode) {
114                if (buttonMode == 0) return "blue white--text";
115                if (buttonMode == 1) return "red white--text";

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 true only if they refer to the same object.
If both operands are null or both operands are undefined, return true.
If either operand is NaN, return false.
Otherwise, compare the two operand's values:
- Numbers must have the same numeric values. +0 and -0 are considered to be the same value.
- Strings must have the same characters in the same order.
- Booleans must be both true or both false.

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

CIDARLAB / 3DuF

Bad Practice

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