详解JavaScript对数组操作（添加/删除/截取/排序

var arr = new Array();

var arr = [];

arrayJson.dataList.splice(0,arr.length);

/**
 * 假设数组的长度值为偶数，如何将指定元素添加到数组中间位置。
 */
function array_middle_insert() {
	var arr = ['1','2','3','4','5','6'];
	if(0 == arr.length % 2) {	//偶数
		arr.splice(arr.length / 2,0,'中间添加');
	}
	//["1","2","3","中间添加","4","5","6","7"]
	console.log(JSON.stringify(arr));
}

/**
 * concat:连接两个或者多个数组，并且返回该数组
 * 语法：array.concat(object,object,......);
 */
function array_concat() {
	var arr = [{index:'0'},{address:'1'}];
	var arr_1 = [{index:'3'},{index:'4'}];
	
	var newArr = arr.concat(arr_1);
	//[{"index":"0"},{"address":"1"},{"index":"3"},{"index":"4"}]
	console.log(JSON.stringify(newArr));
}

/**
 * join():通过指定字符对数据进行分割，返回字符串。
 * jon(分隔符);
 */
function array_join() {
	var arr = ['1','2','3'];
	var str = arr.join('-');
	//1-2-3
	console.log(str);
}

/**
 * pop():删除数组的最后一个对象，返回该删除元素的值
 */
function array_pop() {
	var arr = [{index:'0'},{address:'1'}];
	var pop_data = arr.pop();
	
	//{"address":"1"}
	console.log(JSON.stringify(pop_data));
	//[{"index":"0"}]
	console.log(JSON.stringify(arr));
}

/**
 * push：向数组末尾添加一个或者多个对象。
 * array.push(newObject1,newObject2,.....);
 */
function array_push() {
	//实例化一个数组对象
	var arr = new Array();
	var obj_1 = { index:'1', index:'2'};
	var obj_2 = { index:'3', index:'3'};
	
	arr.push(obj_1,obj_2);
	//[{"index":"2"},{"index":"3"}]
	console.log(JSON.stringify(arr));
}

/**
 * shift():该方法用户删除数组的第一个对象，并返回删除的元素
 */
function array_shift() {
	var arr = [{index:'0'},{address:'1'}];
	var shift_data = arr.shift();
	//{"index":"0"}
	console.log(JSON.stringify(shift_data));
	//[{"address":"1"}]
	console.log(JSON.stringify(arr));
}

/**
 * slice()：从已知数组中返回指定选中的数据,该操作不会修改原数组的数据
 * slice(start,end);
 */
function array_slice() {
	var arr = ['1','2','3','4','5'];
	var new_array = arr.slice(1,arr.length);
	//["2","3","4","5"]
	console.log(JSON.stringify(new_array));
	//["1","2","3","4","5"]
	console.log(JSON.stringify(arr));
}

/**
 * sort():方法用户对数组的排序
 * sort(sortby)		sortby可选，必须是函数。如调用方法没有使用参数，则按字母顺序进行排序。
 */
function array_sory() {
	var arr = [{index:'500'},{index:'40'},{index:'100'},{index:'50'}];
	var new_array = arr.sort(function(a,b) {
		var n1 = Number(a.index);
		var n2 = Number(b.index);
		return n1 - n2;
	});
	//[{"index":"40"},{"index":"50"},{"index":"100"},{"index":"500"}]
	console.log(JSON.stringify(new_array));
}

/**
 * 向数组中删除/添加对象，并返回被删除的元素。
 * splice(index,count,item1,item2,......);	
 * index:规定删除/添加项目的起始位置，使用负数从数组的结尾处规定位置。
 * count:规定要删除项目的数量
 * item1,item2...:向项目中添加添加新的对象
 */
function array_splice() {
	var arr = ['1','2','3'];
	var new_array = arr.splice(0,2,'4','5');
	//["1","2"]
	console.log(JSON.stringify(new_array));
	//["4","5","3"]
	console.log(JSON.stringify(arr));
}

/**
 * 向数组开头添加一个或者多个元素，并返回新的长度。
 */
function array_unshift() {
	var arr = [{index:'0'},{address:'1'}];
	var obj_1 = {index:'2'};
	var obj_2 = {index:'3'};
	var length = arr.unshift(obj_1,obj_2);
	//4
	console.log(length);
	//[{"index":"2"},{"index":"3"},{"index":"0"},{"address":"1"}]
	console.log(JSON.stringify(arr));
}

[
	{
		"dateMonth":"05",
		"hopeMoney":"12000",
		"data":[
			{
				"brickId":"1",
				"brickYear":"2017-05-15",
				"brickWeek":"星期二",
				"brckInfo":[
					{
						"bringMoneyOrExpenditure":"5000",
						"brickClass":"工资",
						"brickIcon":"ion-ios-star-outline"
					},
					{
						"bringMoneyOrExpenditure":"-2000",
						"brickClass":"其他",
						"brickIcon":"ion-ios-star-outline"
					}
				]
			},
			{
				"brickId":"1",
				"brickYear":"2017-05-02",
				"brickWeek":"星期六",
				"brckInfo":[
					{
						"bringMoneyOrExpenditure":"10000",
						"brickClass":"工资",
						"brickIcon":"ion-ios-star-outline"
					}
				]
			}
		]
	},
	{
		"dateMonth":"04",
		"hopeMoney":"12000",
		"data":[
			{
				"brickId":"1",
				"brickYear":"2017-04-15",
				"brickWeek":"星期一",
				"brckInfo":[
					{
						"bringMoneyOrExpenditure":"5000",
						"brickClass":"工资",
						"brickIcon":"ion-ios-star-outline"
					}
				]
			}
		]
	}
]