Ts/Js 實現抽獎功能--根據物品權重計算

 　/**
     * 
     * @param vWeight 權重的數組：例如【1,1,1,1,1】
     * @returns //注意：返回的下標加1（佔第幾個）
     */
　　public static GetPrize(vWeight: number[]): number {
        //計算權重之和  prev 是前一次累加後的數值，currVal 是本次待加的數值
        let weightSum = vWeight.reduce((prev, currVal) => {
            return prev + currVal;
        }, 0);
        let random = Math.ceil(Math.random() * weightSum);
        console.log("random ---->" + random);
        let count = 0;
        for (let i = 0; i < vWeight.length; i++) {
            count += vWeight[i];
            if (random <= count) {
                return i + 1;
            }
        }
    }