js版:
<input oninput= (val) => {if(val.length>11)return val.sliece(0,11)}>
vue版:
<el-input v-on:input="watchInput" v-model='input'></el-input>
data(){
return {
input:''
}
},
methods:{
watchInput(val){
if(val.length>10){
this.input = val.slice(0,10)
}
}
}