<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><body><div id="mId"></div><script type="text/javascript">
var div = document.getElementById('mId');</script></body></html>
2.利用document.getElementsByName(‘name名’);
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><body><div name="mName"></div><script type="text/javascript">
var div = document.getElementsByName('mName')[0];//获取到了div</script></body></html>
3.利用document.getElementsByTagName(‘标签名’);
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><body><div>1</div><div>2</div><div>3</div><div>4</div><script type="text/javascript">
var div = document.getElementsByTagName('div')[0];//获取到了div //element加了s表示是集合 获取的是一组元素 是伪数组//可以在获取元素后面加[写你想要的那个元素 数字表示 下标是0]; </script></body></html>
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><body><div class="mClass">1</div><div>2</div><div>3</div><div>4</div><script type="text/javascript">
var div = document.getElementsByClassName('mClass')[0];</script></body></html>
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Document</title></head><body><div class="mClass">1</div><div>2</div><div>3</div><div>4</div><script type="text/javascript">
var div = document.querySelectorAll('.mClass')[0];//是个集合可以选择多个</script></body></html>