How to use JS to verify input numbers and retain decimals

This time I will show you how to use JS to implement the function of verifying input numbers and retaining decimals, and how to use JS to implement the functions of verifying input numbers and retaining decimals. What are the precautions?. Here are practical cases. Let’s take a look. take a look.

1. Verification method validationNumber(e, num) e represents the label object, num represents the number of decimal places to be retained

function validationNumber(e, num) {
      var regu = /^[0-9]+\.?[0-9]*$/;
      if (e.value != "") {
        if (!regu.test(e.value)) {
          alert("请输入正确的数字");
          e.value = e.value.substring(0, e.value.length - 1);
          e.focus();
        } else {
          if (num == 0) {
            if (e.value.indexOf('.') > -1) {
              e.value = e.value.substring(0, e.value.length - 1);
              e.focus();
            }
          }
          if (e.value.indexOf('.') > -1) {
            if (e.value.split('.')[1].length > num) {
              e.value = e.value.substring(0, e.value.length - 1);
              e.focus();
            }
          }
        }
      }
    }

2. Verification integer

<asp:TextBox ID="txtNg" name="txtNg" runat="server" Height="16px" Width="98px" Font-Size="9pt"
   CssClass="EditTextBox" onpropertychange="validationNumber(this,0)"></asp:TextBox>

3. One digit is reserved Decimal

<asp:TextBox ID="txtChglinecost" name="txtChglinecost" runat="server" Height="16px" Width="98px" Font-Size="9pt" 
   CssClass="EditTextBox" onpropertychange="validationNumber(this,1)"></asp:TextBox>

4. Keep two decimal places

<asp:TextBox ID="txtStdyr" name="txtStdyr" runat="server" Height="16px" Width="98px" Font-Size="9pt" 
   CssClass="EditTextBox" onpropertychange="validationNumber(this,2)"></asp:TextBox>

5. Keep three decimal places

Just put validationNumber(this,3) in the method Just change the second parameter to 3.

Keep four decimal places, keep five decimal places, and so on...

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website !

Recommended reading:

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How to deal with async/await wasteful performance issues

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