disallow deleting variables (no-delete-var)
The purpose of the delete operator is to remove a property from an object. Using the delete operator on a variable might lead to unexpected behavior.
This rule disallows the use of the delete operator on variables.
If ESLint parses code in strict mode, the parser (instead of this rule) reports the error.
Examples of code for this rule:
/*eslint no-delete-var: "error"*/ var x; delete x;