---
title: isIDStart
framework: swift
role: symbol
role_heading: Instance Property
path: swift/unicode/scalar/properties-swift.struct/isidstart
---

# isIDStart

A Boolean value indicating whether the scalar is one which is recommended to be allowed to appear in a starting position in a programming language identifier.

## Declaration

```swift
var isIDStart: Bool { get }
```

## Discussion

Discussion Applications that store identifiers in NFKC normalized form should instead use isXIDStart to check whether a scalar is a valid identifier character. This property corresponds to the “ID_Start” and the “Other_ID_Start” properties in the Unicode Standard.