Question

我循环遍历数组中的元素。如果某个值不在特定范围内，我想删除该元素（该值与之关联）。

这是我到目前为止的内容（参见下面的代码） - 我使用pop方法删除元素，但是数组中的最后一个元素总是被删除而不是if / then中的元素/值声明。我也尝试过拼接方法，但我无法让它工作。关于如何做到这一点的任何想法？

    var h = [
    	["29","Verbena St", "500", "2", "2,702"],
    	["36", "Quitman St", "400", "2", "1,700"],
    	["32", "Alan Dr", "500", "2", "2,408"],
    	["34", "Newton St", "300", "2", "1,954"],
    	["30", "Soth Pl", "400", "2", "1,509"]
    ];

    var hs = [
     	["Verbena St"],
    	["Quitman St"],
        ["Alan Dr"],
     	["Newton St"],
     	["Soth Pl"]
    ];


function Location (){

    for (var r = 0; r <= h.length; r++){
        var p = h[r][0];
	    var address = h[r][1]; // Get address
        if (p >= 21 && p <= 33 && address == hs[r]){
            console.log(address);
        }
        else {
            console.log(address + " - OVER 33");
            h.pop(address);
            console.log(address + " - REMOVED");
        }
   }
};

Location();

Answer 1

在迭代数组时从数组中删除元素并不是一个好习惯，相反，您可以使用filter()对其进行过滤，如下所示：

var h = [
  ["29","Verbena St", "500", "2", "2,702"],
  ["36", "Quitman St", "400", "2", "1,700"],
  ["32", "Alan Dr", "500", "2", "2,408"],
  ["34", "Newton St", "300", "2", "1,954"],
  ["30", "Soth Pl", "400", "2", "1,509"]
];

var hs = [
  ["Verbena St"],
  ["Quitman St"],
  ["Alan Dr"],
  ["Newton St"],
  ["Soth Pl"]
];

function Location (){
  h = h.filter(function(r, i){ // r = value, i = index
    var p=r[0];
    var address = r[1]; // Get address
    return p >= 21 && p <= 33 && address == hs[i];
  });
};

Location();
console.log(h);

或者，如果你想显示消息，你可以使用另一个数组，只推送你想要的元素（更好地使用forEach）：

var h = [
  ["29","Verbena St", "500", "2", "2,702"],
  ["36", "Quitman St", "400", "2", "1,700"],
  ["32", "Alan Dr", "500", "2", "2,408"],
  ["34", "Newton St", "300", "2", "1,954"],
  ["30", "Soth Pl", "400", "2", "1,509"]
];

var hs = [
  ["Verbena St"],
  ["Quitman St"],
  ["Alan Dr"],
  ["Newton St"],
  ["Soth Pl"]
];

function Location (){
  var g = [];
  h.forEach(function(r, i){ // r = value, i = index
    var p = r[0];
    var address = r[1]; // Get address
    if (p >= 21 && p <= 33 && address == hs[i]){
    	console.log(address);
      g.push(r); // push it
    }
    else{
      console.log(address + " - OVER 33 - REMOVED"); // do nothing
    }
  });
  h = g;
}

Location();
console.log(h);

Answer 2

为了删除数组的元素，你可以从最后循环并在必要时拼接，因为下一个较小的索引不会受到影响。

function updateLocation() {
    var address, p, r = h.length;
    while (r--) {
        p = h[r][0];
        address = h[r][1]; // Get address
        if (p >= 21 && p <= 33 && address == hs[r]) {
            console.log(address);
        } else {
            console.log(address + " - OVER 33");
            h.splice(r, 1);
            console.log(address + " - REMOVED");
        }
    }
}

var h = [["29", "Verbena St", "500", "2", "2,702"], ["36", "Quitman St", "400", "2", "1,700"], ["32", "Alan Dr", "500", "2", "2,408"], ["34", "Newton St", "300", "2", "1,954"], ["30", "Soth Pl", "400", "2", "1,509"]],
    hs = [["Verbena St"], ["Quitman St"], ["Alan Dr"], ["Newton St"], ["Soth Pl"]];

updateLocation();
console.log(h);

如果一个值通过if / then语句从数组中删除元素 - Javascript

2 个答案: