Limit input input input box can only xxx

Limit input input input box can only xxx

• Use onkeyup event, there are bug, that is, in the Chinese input method status, just press Enter after input Chinese characters, will directly enter the letters
• Use onchange event, after typing in, lose focus when only input will get results, not just respond when input
• Use oninput event, the perfect solution to these two problems, the test had no other problems.

Principle that will trigger events in the input event and will replace the regular expression will replace non-compliant (deleted) by character

Input uppercase and lowercase letters, numbers, underscores:

<input type="text" oninput="value=this.value.replace(/[^\w_]/g,'');"> 
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Enter lowercase letters, numbers, underscores:

<input type="text" oninput="value=this.value.replace(/[^a-z0-9_]/g,'');"> 
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Enter numbers and points

<input type="text" oninput="value=value.replace(/[^\d.]/g,'')">
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Input Chinese:

<input type="text" oninput="value=this.value.replace(/[^\u4e00-\u9fa5]/g,'')">  
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type in data:

<input type="text" oninput="value=this.value.replace(/\D/g,'')">  
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Enter English:

<input type="text" oninput="value=this.value.replace(/[^a-zA-Z]/g,'')">  
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Enter the Chinese, numbers, English:

<input oninput="value=value.replace(/[^\w\u4E00-\u9FA5]/g, '')">  
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Enter the numbers and letters:

<input oninput="value=value.replace(/[\W]/g,'')">  
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You can only enter letters and numbers, you can not enter Chinese

<input oninput="value=value.replace(/[^\w\.\/]/ig,'')">
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You can only enter numbers and

<input oninput="value=value.replace(/[^\d|chun]/g,'')">
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Reproduced in: https: //juejin.im/post/5d05e86b6fb9a07ef90c97e9