let x = 55
let level = $branches.ifElse((ifElse) => {
    ifElse.add(() => {
        return x >= 90 && x < 100
    }, () => {
        return "优秀"
    })
    ifElse.add(() => {
        return x >= 80 && x < 90
    }, () => {
        return "好"
    })
    ifElse.add(() => {
        return x >= 70 && x < 80
    }, () => {
        return "良"
    })
    ifElse.add(() => {
        return x >= 60 && x < 70
    }, () => {
        return "及格"
    })
    ifElse.addDefault(() => {
        return "不及格"
    })
})
$console.log(level)