数组去重：
if(this.cardL.length < 1) {
this.cardL = res.data.couponList
} else {
this.cardL = this.cardL.concat(res.data.couponList)
let temp = []; //一个新的临时数组
this.cardL.forEach((vt, i) => {
let No = temp.findIndex(vj => vj.couponId === vt.couponId)
if(No < 0 ){
temp.push(this.cardL[i]);
}
// if (this.cardL.length - 1 === i) this.cardL = temp
});
this.cardL = temp
}
