vue中methods有值但是传到mounted却是undefined，这是为什么 该怎么办？

Question

vue中methods有值但是传到mounted却是undefined，这是为什么 该怎么办？

mounted() {
      this.$nextTick(() => {
        getPeixianMapData().then(res => {
          let top10Datas = this.getPeixianMapValue()
          console.log('top10Datas', top10Datas)
          this.initChart(top10Datas)
        })
      })
},

methods: {
      getPeixianMapValue() {
        getPeixianMapValue(0, 10000, {}).then(res => {
          let rd = res.data.content
          function compare(property){
            return function(a,b){
              let value1 = a[property];
              let value2 = b[property];
              return value2 - value1;        
            }
          }
          let sortData = rd.sort(compare('value'))
          let top10Data = []
          for (let i = 0; i < 10; i++) {
            top10Data.push(sortData[i])
          }
          console.log('top10', top10Data)
          return top10Data
        })
      },

      ......
}

Answer 1

        getPeixianMapValue() {
            return new Promise((resolve) => {
            getPeixianMapValue(0, 10000, {}).then(res => {
              let rd = res.data.content

              function compare(property) {
                return function (a, b) {
                  let value1 = a[property];
                  let value2 = b[property];
                  return value2 - value1;
                }
              }
              let sortData = rd.sort(compare('value'))
              let top10Data = []
              for (let i = 0; i < 10; i++) {
                top10Data.push(sortData[i])
              }
              console.log('top10', top10Data)
              resolve(top10Data)
            })
          })

        }