//1 instanceof var obj = []; console.log(obj instanceof array);//ture //2 使用数组的 console.log(array.isarray(obj));//ture
var arr1 = [10, 20, 30]; var arr2 = [40, 50, 60]; console.log(arr1.concat(arr2));
var arr = [1000, 2000, 3000]; //a----: 元素的值 //b----: 索引的值 //c----:谁调用了这个方法,那么c就是谁---->arr var flag = arr.every(function (a, b) { //console.log(a+"==="+b+"===="+c); return a > 2000;//数组中的每个元素的值都要大于2000的情况,最后才返回true });
var arr = ["小明明lkko", "小曹操674", "小白白bd", "笑眯眯a"]; var flag = arr.every(function (ele, index) { //数组中的每个元素的长度是不是大于4 return ele.length > 4; }); console.log(flag);//false
var arr = [10, 20, 30, 40, 50, 60, 70, 80]; var newarr = arr.filter(function (ele) {//ele---每个元素 return ele > 40; }); console.log(newarr);
var arr = [10, 0, 20, 0, 40, 0, 60, 100]; var newarr = arr.filter(function (ele) { return ele != 0; }); console.log(newarr);
var arr = [10, 20, 30, 40, 50]; var result = arr.push(100); console.log(result);// 6 新数组的长度 console.log(arr);//[10, 20, 30, 40, 50, 100]
var arr = [10, 20, 30, 40, 50]; var result = arr.pop(); console.log(result); //50 console.log(arr); //[10, 20,30, 40]
var arr = [10, 20, 30, 40, 50]; var result = arr.shift(); console.log(result); //10 console.log(arr);//[20, 30, 40, 50]
var arr = [10, 20, 30, 40, 50]; var result = arr.unshift(100);// console.log(result); console.log(arr);
var arr = [10, 20, 30, 40]; arr.foreach(function (ele, index) { console.log(ele + '======' + index); });
var arr = [10, 20, 30, 40]; var index = arr.indexof(300); console.log(index);
var arr = ["小白", "小黑", "小红", "小芳", "小绿", "小苏"]; var str = arr.join("|"); console.log(str);
var numbers = [1, 4, 9]; var roots = numbers.map(math.sqrt); console.log(roots);
var arr = [10, 20, 30, 40, 50]; arr.reverse();//反转 console.log(arr);
var arr = [1, 40, 20, 10, 100]; //a---arr[j] //b---arr[j+1] arr.sort(function (a, b) { if (a > b) { return 1; } else if (a == b) { return 0; } else { return -1; } }); console.log(arr);
var arr = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100]; var newarr = arr.slice(3, 7); console.log(newarr);
var myfish = ['angel', 'clown', 'mandarin', 'sturgeon']; // myfish.splice(2, 0, 'drum'); // 在索引为2的位置插入'drum' // myfish 变为 ["angel", "clown", "drum", "mandarin", "sturgeon"] myfish.splice(2, 1); // 从索引为2的位置删除一项(也就是'drum'这一项) console.log(myfish); // myfish 变为 ["angel", "clown", "mandarin", "sturgeon"]
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