--- ruleName: no-for-in-array description: Disallows iterating over an array with a for-in loop. descriptionDetails: | A for-in loop (`for (var k in o)`) iterates over the properties of an Object. While it is legal to use for-in loops with array types, it is not common. for-in will iterate over the indices of the array as strings, omitting any "holes" in the array. More common is to use for-of, which iterates over the values of an array. If you want to iterate over the indices, alternatives include: array.forEach((value, index) => { ... }); for (const [index, value] of array.entries()) { ... } for (let i = 0; i < array.length; i++) { ... } optionsDescription: Not configurable. options: null optionExamples: - 'true' requiresTypeInfo: true type: functionality optionsJSON: 'null' layout: rule title: 'Rule: no-for-in-array' ---