HTML-CSS-JavaScript综合

1.JavaScript

1.1.GET

获取下拉框选中option的value

$("#id").val()

1.2.SET

设置自定义属性的值

document.getElementById("input1").setAttribute('ind','def');
$('#input1').attr('ind','xyz');

参考 :  https://blog.youkuaiyun.com/qq_34599639/article/details/78105170

设置下拉框选中

// 使value为2的选中
document.getElementById("mysel").value="2";

// 选中第一个
document.getElementById("mysel")[0].selected = true;

参考 : https://www.jb51.net/article/76547.htm 

设置input的值

document.getElementById("input1").value = '456';
$('#input1').val('789');

1.3.判断

为空判断

if(user == null || typeof(user) == "undefined" || user.replace(/\s*/g, "").length == 0 || user == ''){
		
	}

1.4.ajax

同步

async:false,

get

	$.ajax({
		url : '/test',
		type : 'get',
		data : {
			"p1" : "1"
 
		},
		success : function(data) {
 
		}
	});

post json

参考 : Jquery AJAX post提交json示例 - 简书

	$.ajax({
		url: address + '/post/test',
		type: 'post',
		contentType : "application/json",
		data: JSON.stringify(param),
		success: function(data) {
			console.log(data)
		}
	});

1.5.加减乘除精度丢失

参考 : js加减乘除丢失经度问题_yongqi_wang的博客-优快云博客

var CMX = CMX || {};
/**
 ** 加
 **/
CMX.add = function (arg1, arg2) {
  if(arg1 == undefined && arg2 == undefined)return 0;
  if(arg1 == undefined)arg1 = 0;
  if(arg2 == undefined)arg2 = 0;
  var r1, r2, m, c;
  try {
    r1 = arg1.toString().split(".")[1].length;
  } catch (e) {
    r1 = 0;
  }
  try {
    r2 = arg2.toString().split(".")[1].length;
  } catch (e) {
    r2 = 0;
  }
  c = Math.abs(r1 - r2);
  m = Math.pow(10, Math.max(r1, r2));
  if (c > 0) {
    var cm = Math.pow(10, c);
    if (r1 > r2) {
      arg1 = Number(arg1.toString().replace(".", ""));
      arg2 = Number(arg2.toString().replace(".", "")) * cm;
    } else {
      arg1 = Number(arg1.toString().replace(".", "")) * cm;
      arg2 = Number(arg2.toString().replace(".", ""));
    }
  } else {
    arg1 = Number(arg1.toString().replace(".", ""));
    arg2 = Number(arg2.toString().replace(".", ""));
  }
  return (arg1 + arg2) / m;
};
 
/**
 ** 减
 **/
CMX.sub = function (arg1, arg2) {
  if(arg1 == undefined && arg2 == undefined)return 0;
  if(arg1 == undefined)arg1 = 0;
  if(arg2 == undefined)arg2 = 0;
  var r1, r2, m, n;
  try {
    r1 = arg1.toString().split(".")[1].length;
  } catch (e) {
    r1 = 0;
  }
  try {
    r2 = arg2.toString().split(".")[1].length;
  } catch (e) {
    r2 = 0;
  }
  m = Math.pow(10, Math.max(r1, r2)); //last modify by deeka //动态控制精度长度
  n = (r1 >= r2) ? r1 : r2;
  return Number(((arg1 * m - arg2 * m) / m).toFixed(n));
};
 
/**
 ** 乘
 **/
CMX.mul = function (arg1, arg2) {
  if(arg1 == undefined || arg2 == undefined)return 0;
  var m = 0, s1 = arg1.toString(), s2 = arg2.toString();
  try {
    m += s1.split(".")[1].length;
    m += s2.split(".")[1].length;
  } catch (e) {}
  return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
};
 
/**
 ** 除
 **/
CMX.div = function (arg1, arg2) {
  if(arg1 == undefined || arg2 == "" || arg2 == undefined || arg2 == 0)return 0;
  var t1 = 0, t2 = 0, r1, r2;
  try {
    t1 = arg1.toString().split(".")[1].length;
    t2 = arg2.toString().split(".")[1].length;
  } catch (e) {}
  with (Math) {
    r1 = Number(arg1.toString().replace(".", ""));
    r2 = Number(arg2.toString().replace(".", ""));
    return (r1 / r2) * pow(10, t2 - t1);
  }
};

1.6.页面缩放

0.5为50%

		document.body.style.zoom=0.5;

2.CSS

3.HTML