Initialization in variable declarations against recommended approach JS-0119
Anti-pattern
Minor
a year ago
—
2 years old
Variable 'streamChatArea' should be initialized on declaration.
31 thumbnail: {},
32}
33
34let rightColumn, streamChatArea;35let chatArea;
36let inputArea, inputSendButton;
37let iconSelectorParent, iconSelectorPosition;Variable 'chatArea' should be initialized on declaration.
32}
33
34let rightColumn, streamChatArea;
35let chatArea;36let inputArea, inputSendButton;
37let iconSelectorParent, iconSelectorPosition;
38let iconArea;Variable 'inputSendButton' should be initialized on declaration.
33
34let rightColumn, streamChatArea;
35let chatArea;
36let inputArea, inputSendButton;37let iconSelectorParent, iconSelectorPosition;
38let iconArea;
39let profileArea;Variable 'iconSelectorParent' should be initialized on declaration.
34let rightColumn, streamChatArea;
35let chatArea;
36let inputArea, inputSendButton;
37let iconSelectorParent, iconSelectorPosition;38let iconArea;
39let profileArea;
40Variable 'iconSelectorPosition' should be initialized on declaration.
34let rightColumn, streamChatArea;
35let chatArea;
36let inputArea, inputSendButton;
37let iconSelectorParent, iconSelectorPosition;38let iconArea;
39let profileArea;
40
Description
In JavaScript, variables can be assigned during declaration, or at any point afterwards using an assignment statement. For example, in the following code, foo is initialized during declaration, while bar is initialized later.
var foo = 1;
var bar;
if (foo) {
bar = 1;
} else {
bar = 2;
}
Bad Practice
function foo() {
var bar;
let baz;
}
Recommended
function foo() {
var bar = 1;
let baz = 2;
const qux = 3;
}