Iteration only the values by using the key

 loadPrimaryTrendLine()

  {

    this._dashboardService.getPrimaryTrendLine(res =>{

      let linecharts = res[0];  

      Object.keys(linecharts).forEach(key => {

        this.PrimaryTrendLine.push(linecharts[key]);

      });

     })

  }                          

Json : Api Hit (http://127.0.0.1:8000/app_dashboard/primary_trend_line)

[

    {

        "primary_01_value": 0,

        "primary_02_value": 1836.0,

        "primary_03_value": 133785.096

    }

]