如何檢查jQuery中空格的textfield

Question

我有一個表單。我想要驗證，以便它會檢查用戶是否輸入空格。如果它的空白處顯示錯誤。我怎麼能這樣做？

Answer 1

使用jQuery.trim(str)刪除空格或製表符，您可以驗證。

http://api.jquery.com/jQuery.trim/

Answer 2

function doValidations(){ 
    if(jQuery.trim($(".className").val())==""){ 
    alert("error message"); 
    return false;  
    }else{ 
    return true; 
    } 
} 

<input type="submit" onclick="return doValidations();"> 

Answer 3

如果要檢測是否存在任何空白都通過用戶的輸入字符串，

var str = $("input").val(); 
if(str.indexOf(" ") !== -1) 
{ 
    alert("bad input"); 
} 

例子：http://jsfiddle.net/pYquc/

Answer 4

Try this usong javascript: 
var v = document.form.element.value; 
var v1 = v.replace("",""); 
if(v1.length == 0){ 
alert("error"); 
} 

OR you can use following functions: 

// whitespace characters 
     var whitespace = " \t\n\r"; 

     /****************************************************************/ 

     // Check whether string s is empty. 
     function isEmpty(s) 
     { return ((s == null) || (s.length == 0)) } 

     /****************************************************************/ 

     function isWhitespace (s) 
     { 
      var i; 

      // Is s empty? 
      if (isEmpty(s)) return true; 

      // Search through string's characters one by one 
      // until we find a non-whitespace character. 
      // When we do, return false; if we don't, return true. 

      for (i = 0; i < s.length; i++) 
      { 
       // Check that current character isn't whitespace. 
       var c = s.charAt(i); 

       if (whitespace.indexOf(c) == -1) return false; 
      } 

      // All characters are whitespace. 
      return true; 
     }