如何设置选中的默认选项？

<select name="example">
  <option value="option1">Option 1</option>
  <option value="option2" selected>Option 2</option>
  <option value="option3">Option 3</option>
</select>

document.addEventListener('DOMContentLoaded', function() {
  var selectElement = document.querySelector('select[name="example"]');
  selectElement.value = 'option2'; // 设置默认选中的值
});

import React, { useState } from 'react';

function ExampleSelect() {
  const [selectedOption, setSelectedOption] = useState('option2');

  return (
    <select value={selectedOption} onChange={(e) => setSelectedOption(e.target.value)}>
      <option value="option1">Option 1</option>
      <option value="option2">Option 2</option>
      <option value="option3">Option 3</option>
    </select>
  );
}

export default ExampleSelect;

<select [(ngModel)]="selectedOption">
  <option value="option1">Option 1</option>
  <option value="option2">Option 2</option>
  <option value="option3">Option 3</option>
</select>

import { Component } from '@angular/core';

@Component({
  selector: 'app-example-select',
  templateUrl: './example-select.component.html',
  styleUrls: ['./example-select.component.css']
})
export class ExampleSelectComponent {
  selectedOption = 'option2';
}

<template>
  <select v-model="selectedOption">
    <option value="option1">Option 1</option>
    <option value="option2">Option 2</option>
    <option value="option3">Option 3</option>
  </select>
</template>

<script>
export default {
  data() {
    return {
      selectedOption: 'option2'
    };
  }
};
</script>