js怎么和预期的结果不一样

Question

let datamap = [{alwaysReceive:true,origin:'1',target:'2'},{alwaysReceive:true,origin:'2',target:'5'},{alwaysReceive:false,origin:'3',target:'2'}]
let source = [{id:'1',v:'2',t:"9"},{id:'2',v:'88',t:"2"},{id:'3',v:'0',t:"4"}]
var result = [];
  var alwaysReceiveList = []
  datamap.forEach(dmitem=>{
      var tmp = source.find(sitem=>{
          return  dmitem.origin === sitem.id
      });
      console.log(tmp);
      
      if(tmp){
          tmp.id = dmitem.target;
          console.log('1',tmp);
          
          if(dmitem.alwaysReceive){
              alwaysReceiveList.push(tmp) 
          }
          result.push(tmp);
      }
  });
  console.log(result,alwaysReceiveList);

我想要的是result应该为 result:[{id:'2',v:'2',t:"9"},{id:'5',v:'88',t:"2"},{id:'3',v:'0',t:"4"}]

Answer 1

let datamap = [{alwaysReceive:true,origin:'1',target:'2'},{alwaysReceive:true,origin:'2',target:'5'},{alwaysReceive:false,origin:'3',target:'2'}]
let source = [{id:'1',v:'2',t:"9"},{id:'2',v:'88',t:"2"},{id:'3',v:'0',t:"4"}]
var result = [];
  var alwaysReceiveList = []
  datamap.forEach(dmitem=>{
      var tmp = source.find(sitem=>{
          return  dmitem.origin === sitem.id
      });
      if(tmp){
          //用另外一个变量拷贝，不然会改动到source里的值
          var ttmp = Object.assign({}, tmp);
          ttmp.id = dmitem.target;
          if(dmitem.alwaysReceive){
              alwaysReceiveList.push(ttmp) 
          }
          result.push(ttmp);
      }
  });
  console.log(result,alwaysReceiveList);