1, 看效果

2, 直接cv代码就可以 

@Preview
@Entry
@Component
struct Setting {

  @State
  phone:string = '15555555555'

  maskPhoneNumber(phone:string){
    const start = phone.substring(0,3)
    const end = phone.substring(7)
    return `${start}****${end}`
  }

  build() {
      Column(){
        Text(this.maskPhoneNumber(this.phone))
          .fontSize(30)
    }
    .height('100%')
    .width('100%')
    .justifyContent(FlexAlign.Center)
  }
}