[Bug Report] el-switch's V-model is incorrect when it is introduced into int type.

[KiddoLin]

Element UI version

2.4.1

OS/Browsers version

win10 / Chrome 66.0.3359.117

Vue version

2.5.16

Reproduction Link

https://jsfiddle.net/esn7rfo3/3/

Steps to reproduce

1.将左下栏目的js代码增加
mounted() {
let val = 100;
this.value5 = val;
}

即，整体修改为
var Main = {
data() {
return {
value5: '100'
}
},
mounted() {
let val = 100;
this.value5 = val;
}
};
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')
2.点击左上角运行，发现右侧switch按钮为关闭

3.将 let val = 100; 改为 let val = ‘100’;
4.点击左上角运行，发现右侧switch按钮为开启

What is Expected?

无论v-model的值为 '100' 或 100 ，只要值等于el-switch的active-value，switch按钮为开启

What is actually happening?

左上栏目的html代码中，无论el-switch标签的active-value属性为 active-value="100" 或 active-value=100 ，当value5为 '100'(string) 时皆为开启，当value5 为 100(int) 时皆为关闭。
故，应是对v-model的值为int时判断有误吧

[element-bot]

Translation of this issue:

Element UI version
2.4.1

OS/Browsers version
Win10 / Chrome 66.0.3359.117

Vue version
2.5.16

Reproduction Link
https://jsfiddle.net/esn7rfo3/3/

Steps to reproduce

1. increase the JS code of the left column

Mounted () {
Let Val = 100;

This.value5 = Val;
}

That is, the overall modification is
Var Main = {{

Data () {
Return {

Value5:'100'
}

},
Mounted () {

Let Val = 100;
This.value5 = Val;

}
};

Var Ctor = Vue.extend (Main)
New Ctor ().$mount ('#app')

2. click on the upper left corner to find the right switch button to close.

3. let Val = 100; change to let Val = '100';

4. click on the upper left corner to find the right switch button to open.
   What is Expected?

Whether the value of V-model is'100'or 100, if the value is equal to el-switch active-value, the switch button is opened.
What is actually happening?

In the HTML code of the upper left column, the active-value attribute of the el-switch tag is active-value= "100" or active-value=100, and when value5 is'100'(string), it is closed when value5 is 100 (int).
Therefore, it should be wrong when the value of V-model is int.

[jikkai]

Duplicate of #11381