typescript 手动で确率调整できる样品的なやつ

Posted 2021-05-20

export default <T>(array: T): T | null => {
    const rand = Math.floor(Math.random())
    let index = null
    if (rand > 0.6) {
        index = 0
    } else if (rand <= 0.6 && rand > 0.4) {
        index = 1
    } else if (rand <= 0.4 && rand > 0.3) {
        index = 2
    } else if (rand <= 0.3 && rand > 0.15) {
        index = 3
    } else {
        index = 4
    }
    if (!(array instanceof Array)) return null
    return array[index]
}