Answer: Remove the leading spaces and trailing spaces at both ends of the text box input box: ο onblur = "this.value = this.value.replace (/\ s+| \ s+$/g,''); "

Str is a string with spaces removed:

Delete all spaces:

str = str.replace(/\s+/g，" ")；

Delete two spaces:

str = str.replace(/^\s+|\s+$/g，“”；

Delete the space on the left:

str=str.replace( /^\s*/，' ')；

Delete the space on the right:

str=str.replace(/(\s*$)/g，" ")；