Bootstrap 4 Input Groups
Group form controls and text together on a single line.
Input groups enable you to combine form controls and text on the same line. They are similar to button groups in the sense that, they allow you to align the elements flush against each other.
To create an input group, use Bootstrap's .input-group class for the actual input group. For an element to be appended to the form control, use a <span> with .input-group-text nested inside a <div> with .input-group-append.
Note that input groups are designed for textual <input> elements only.
Text on Both Sides
You can also use .input-group-prepend to prepend an element to the form control. In fact you can have text on both sides of the control.
Size
Use either .input-group-sm or .input-group-lg on the input group to specify the size of all elements. No need to specify these on each element in the group.
Checkboxes & Radio Buttons
You can place checkboxes and radio buttons instead of text.
Button Addons
You can also add buttons to the form control instead of text.
Dropdowns
You can add dropdown menus to the input group.
Split Dropdowns
You can also add split dropdowns to the input group.