js 替换字符串中的字符？

Question

根据'${spet1}sdasdas${spet2}asdasdas${spet3}'这个字符串，我循环出了输入框

this.variableArr =  this.content.match(/\['${']+spet+\d+['}']/g);
for (let [index, value] of  this.variableArr.entries()) {
  this.form.variable\[value\] =  '';
}
let { variable } =  this.form;

this.form.variable = JSON.parse(JSON.stringify(variable));

<el-form-item :label="item"  v-for="(item, index) in  variableArr" :key="index"  prop\="item">
<el-input  v-model="form.variable[item]"  placeholder="请输入"></el-input>
</el-form-item>

绑定好了之后出现以下页面

我想的是一边输入一边修改那一行字符串中的文字，达到模版更改的需求