如果值在数组中使用包括不起作用

Question

我有2个数组：

ids = [a,b,c,d,e,f....];

savedRepods = [e,f];

  function getPoints(){
      for (var i = 0; i < savedRepods.length; i++) {
        if(ids.includes(savedRepods[i]) ) {
          console.log(savedRepods[i]);
        }
      }
  }

我知道值在数组中，但这不会向我显示值console.log(savedRepods[i]);

完整代码：

  /** get saved values from the server */
  var savedRepods = <?php echo json_encode($userPostsInternal); ?> ;
  savedRepods = savedRepods.split(",");

  /** create single arrays for the values */

  var date = [],
      coords = [],
      ids = [],
      metal = [],
      plastic = [],
      paper = [],
      glass = [],
      indirizzo = [];

  /** convert to a variable ALL the other values form the server */

  var array = <?php echo $contents; ?> ;

  /** push single values into correspondent arrays */

  array.map(function(item) {
      coords.push(item.Lat + "," + item.Lng);
      ids.push(item.ID);
      date.push(item.Date);
      plastic.push(item.Plastic);
      paper.push(item.Paper);
      glass.push(item.Glass);
      metal.push(item.Metal);
  });


  /**
   * Now process the response from locationData
   */
  var locations = getPoints();

  /**
   * findLatLang
   */
  function findLatLang(location, geocoder, value) {
      /**
       * Return new Promise what resolves when 
       * the geocoder is successfull
       * and push in the array of promises
       */
      return new Promise(function(resolve, reject) {
          /** Do geocoder */
          geocoder.geocode({
              'location': location
          }, function(results, status) {
              /**
               * If geocoder is Ok
               */
              if (status === 'OK') {
                  /**
                   * When the geocoder is successfull located
                   * resolve the promise and send the response of formate address
                   */
                  resolve([results[0].formatted_address, value]);
              } else {
                  /**
                   * Reject the promise
                   */
                  reject(new Error('Couldnt\'t find the location ' + location));
              }
          })
      })
  }

  /**
   * processData 
   * return an array of promises
   */
  function getPoints(){
      /**
       * Declare a variable of promises that have a geocoder
       */
      let locationData = [];
      for (var i = 0; i < savedRepods.length; i++) {

        if(ids.includes(savedRepods[i]) ) {

          console.log(savedRepods[i]);

          var geocoder = new google.maps.Geocoder;
          var latlngStr = coords[a].split(',', 2);
          var latlng = {
              lat: parseFloat(latlngStr[0]),
              lng: parseFloat(latlngStr[1])
          };

          /**
           * Push geocoder in array of locationdata
           * Send the geocoder object on function and send the map
           */
          locationData.push(findLatLang(latlng, geocoder, a))
        }
      }

      /** return array of promises */
      return locationData;
  }

  Promise.all(locations)
    .then(function(returnVals){
    indirizzo = returnVals;
    doAddress(indirizzo)
  });

  var usedId = [],
      usedMetal = [],
      usedGlass = [],
      usedPaper = [],
      usedLocation = [],
      usedPlastic = [];


      const data = [];

  function doAddress(indirizzo) {
    indirizzo.forEach(function(item){
      var a = item[1];
      var location = item[0];

      let newObj = {};
      newObj.idValue = ids[a];
      newObj.addressValue = location;
      newObj.metalValue = metal[a];
      newObj.glassValue = glass[a];
      newObj.plasticValue = plastic[a];
      newObj.paperValue = paper[a];
      data.push(newObj);

      $("#eachValue ul").append("<li class='list-group-item'>repod id= " + ids[a] + "<br> Indirizzo = " + location + "<br> Metallo = " + metal[a] + ", <br> Plastica = " + plastic[a] + ", <br> Vetro = " + glass[a] + ", <br> Carta = " + paper[a] + "</li>");
    })

    const resultMetal = data.sort((a, b) => b.metalValue - a.metalValue)[0];
    const resultGlass = data.sort((a, b) => b.glassValue - a.glassValue)[0];
    const resultPaper = data.sort((a, b) => b.paperValue - a.paperValue)[0];
    const resultPlastic = data.sort((a, b) => b.plasticValue - a.plasticValue)[0];

    $("#metal p").html("Il repod con id "+resultMetal.idValue+"<br>situato in <br>" + resultMetal.addressValue + "<br> ha consumato più metallo con un valore di " + resultMetal.metalValue);
    $("#vetro p").html("Il repod con id "+resultGlass.idValue+"<br>situato in <br>" + resultGlass.addressValue + "<br> ha consumato più vetro con un valore di " + resultGlass.glassValue);
    $("#plastica p").html("Il repod con id "+resultPlastic.idValue+"<br>situato in <br>" + resultPlastic.addressValue + "<br> ha consumato più plastica con un valore di " + resultPlastic.plasticValue);
    $("#carta p").html("Il repod con id "+resultPaper.idValue+"<br>situato in <br>" + resultPaper.addressValue + "<br> ha consumato più carta con un valore di " + resultPaper.paperValue);


  }

Answer 1

[可能由于数组条目是object类型。 Array.prototype.contains不适用于对象类型。因为在js中：

var a = {
  prop: 'value'
}

var b = {
  prop: 'value'
}

if (a != b) {
  console.log('a is not equal to b');
}

在javascript中=（等于）的运算符检查对于object类型，引用是否相同。引用是对象在内存中的地址。在我的第一个示例中，a和b有其自己的不同引用，因此对于javascript a不等于b。

代替contains，您可以使用some方法，该方法需要回调来手动检查匹配项。这是一个使用some方法查找元素是否存在的示例。

var array = [
  { name: 'Anna', age: 19 },
  { name: 'Sara', age: 17 },
  { name: 'John', age: 21 },
  { name: 'Doe', age: 34 }
]

var john = { name: 'John', age: 21 };

if (array.some((other) => {
  return other.name == john.name && other.age == john.age
})) {
  console.log('John is exists in the array');
}

如果您不想检查每个属性的对象，可以检查JSON.stringfy(other) == JSON.stringfy(john)。