如何在JavaScript中删除数组中的空元素?
是否有一种简单的方法,或者我需要循环并手动删除它们?
如何在JavaScript中删除数组中的空元素?
是否有一种简单的方法,或者我需要循环并手动删除它们?
当前回答
我需要完成同样的任务,并遇到了这个线程。我最终使用数组“join”使用“_”分隔符创建字符串,然后使用正则表达式:-
1. replace "__" or more with just one "_",
2. replace preceding "_" with nothing "" and similarly
3. replace and ending "_" with nothing ""
…然后使用数组“拆分”生成一个已清理的数组:-
var myArr = new Array("","","a","b","","c","","","","","","","","","e","");
var myStr = "";
myStr = myArr.join("_");
myStr = myStr.replace(new RegExp(/__*/g),"_");
myStr = myStr.replace(new RegExp(/^_/i),"");
myStr = myStr.replace(new RegExp(/_$/i),"");
myArr = myStr.split("_");
alert("myArr=" + myArr.join(","));
…或1行代码:-
var myArr = new Array("","","a","b","","c","","","","","","","","","e","");
myArr = myArr.join("_").replace(new RegExp(/__*/g),"_").replace(new RegExp(/^_/i),"").replace(new RegExp(/_$/i),"").split("_");
alert("myArr=" + myArr.join(","));
…或,扩展Array对象:-
Array.prototype.clean = function() {
return this.join("_").replace(new RegExp(/__*/g),"_").replace(new RegExp(/^_/i),"").replace(new RegExp(/_$/i),"").split("_");
};
var myArr = new Array("","","a","b","","c","","","","","","","","","e","");
alert("myArr=" + myArr.clean().join(","));
其他回答
这只会删除空值,而不是虚假值,我认为这是更可取的。
也可以选择删除空值。
这种方法应该比使用拼接快得多。
function cleanArray(a, removeNull) {
var i, l, temp = [];
l = a.length;
if (removeNull) {
for (i = 0; i < l; i++) {
if (a[i] !== undefined && a[i] !== null) {
temp.push(a[i]);
}
}
} else {
for (i = 0; i < l; i++) {
if (a[i] !== undefined) {
temp.push(a[i]);
}
}
}
a.length = 0;
l = temp.length;
for (i = 0; i < l; i++) {
a[i] = temp[i];
}
temp.length = 0;
return a;
}
var myArray = [1, 2, , 3, , 3, , , 0, , null, false, , NaN, '', 4, , 4, , 5, , 6, , , , ];
cleanArray(myArray);
myArray;
使用正则表达式筛选出无效条目
array = array.filter(/\w/);
filter + regexp
这是我清理空字段的解决方案。
从费用对象开始:仅获取可用属性(带贴图)筛选空字段(带筛选器)将结果解析为整数(带映射)
fees.map( ( e ) => e.avail ).filter( v => v!== '').map( i => parseInt( i ) );
您应该使用filter获取不含空元素的数组。ES6示例
const array = [1, 32, 2, undefined, 3];
const newArray = array.filter(arr => arr);
简单ES6
['a','b','',,,'w','b'].filter(v => v);