1. The hidden part of the number, such as phone number, ID number
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function (str,start,length,mask_char){
return str.replace(str.substr(start,length),
Array(length+
1).join(mask_char||
"*"))
}
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2. Obtain a random number within the specified range
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function Randum ( mention maxnum )
{
return
Math
.floor (My +
Math
.random () * (maxnum memory));
}
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randNum (0,10) is obtained random number between 0 and 9
3. Select All, Select None
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<div>
<input type="checkbox" id="checkAll"/>全选
< The INPUT of the type = "the CheckBox" />
eating
< The INPUT of the type = "the CheckBox" />
Sleeping
< The INPUT of the type = "the CheckBox" />
play Peas
</div>
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was
checkAll =
document
.getElementById (
'checkAll'
);
var checkBoxs =
document.getElementsByTagName(
'input');
大专栏
常用JS代码片段s="line">
var select =
false;
checkAll.addEventListener(
'click',
function(){
select = !select;
for(
let i
in checkBoxs){
checkBoxs[i].checked = select;
}
},
false)
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4.js原生判断元素是否隐藏
当容器元素的style.display 被设置为 “none”时（IE和Opera除外），offsetParent属性返回 null。
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var isHidden =
function (element) {
return (element.offsetParent ===
null);
};
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5.jquery中判断对象是否为空对象
空对象{}肯定是没有属性的，所以通过遍历他的属性来判断它是否是空对象
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function isEmptyObject(e) {
var t;
for (t
in e)
return !
1;
return !
0
}
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5.数组去重
判断当前元素的位置是否是该元素第一次出现的位置，如果不是说明元素重复。indexOf是查找元素第一次出现位置的索引值
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function uniq(array){
return
Array.prototype.filter.call(array,
function(item,idx){
return array.indexOf(item) == idx;
})
}
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