Below I have summarized various methods to delete spaces, including deleting spaces before and after deletion, intermediate spaces, and continuous spaces. For more information, see.
Method 1:
In my opinion, the best method is to use regular expressions, which is the core principle.
Secondly, this method uses the prototype attribute of JavaScript.
In fact, you can use functions without using this attribute, but it is more convenient to use it later.
Next let's take a look at how this attribute is used.
Returns a reference to an object type prototype.
ObjectName. prototype
The objectName parameter is the object name.
Description
The prototype attribute provides a set of basic functions of the object class. The new instance of the object "inherits" the operation that is granted to the object prototype.
For example, you want to add a method to the Array object to return the maximum element value in the Array. To accomplish this, declare the function, add it to Array. prototype, and use it.
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Function array_max (){ Var I, max = this [0]; For (I = 1; I <this. length; I ++) { If (max <this [I]) Max = this [I]; } Return max; } Array. prototype. max = array_max; Var x = new Array (1, 2, 3, 4, 5, 6 ); Var y = x. max (); |
After the code is executed, y saves the maximum value in array x, or 6.
All internal JScript objects have the read-only prototype attribute. You can add features for the prototype as in this example, but the object cannot be assigned different prototypes. However, user-defined objects can be assigned to new prototypes.
The method and attribute list of each internal object in this language reference specifies which parts of the object prototype and which parts are not.
Below is the original code
Program code
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<Script language = "JavaScript"> <! -- // Source: online collection // Made by yaosansi 2005-12-02 // For more visit http://www.bKjia. c0m // Trim (), Ltrim (), RTrim () String. prototype. Trim = function () { Return this. replace (/(^ s *) | (s * $)/g ,""); } String. prototype. LTrim = function () { Return this. replace (/(^ s *)/g ,""); } String. prototype. RTrim = function () { Return this. replace (/(s * $)/g ,""); } // --> </SCRIPT> |
Next let's take a look at "/s" in the Js script"
S matches any blank characters, including spaces, tabs, and page breaks. It is equivalent to [fnrtv].
Please note that it is lowercase s
Jquery deletes Spaces
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$. Trim (str) |
Regular Expression Replacement space
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<Html> <Head> <Title> IE9 closed-test JS-related empty spaces </title> </Head> <Script> Function clearSpace (inputO ){ Var valueText = inputO. value; // Remove leading and trailing Spaces Var text1 = valueText. replace (/^ s +/, ""). replace (/s + $ /,""); // Remove all spaces Var text2 = valueText. replace (/[]/g ,""); // Remove the leading space Var text3 = valueText. replace (/^ s + /,""); // Remove the space Var text4 = valueText. replace (/s + $ /,""); Alert ("=" + text1 + "= "); Alert ("=" + text2 + "= "); Alert ("=" + text3 + "= "); Alert ("=" + text4 + "= "); } </Script> <Body> <Input type = "text" id = "appNo" onblur = "clearSpace (this);"/> </Body> </Html> |
Traverse and delete Spaces
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// For the user to call Function trim (s ){ Return trimRight (trimLeft (s )); } // Remove the left blank Function trimLeft (s ){ If (s = null ){ Return ""; } Var whitespace = new String ("tnr "); Var str = new String (s ); If (whitespace. indexOf (str. charAt (0 ))! =-1 ){ Var j = 0, I = str. length; While (j <I & whitespace. indexOf (str. charAt (j ))! =-1 ){ J ++; } Str = str. substring (j, I ); } Return str; } // Remove the blank www. bKjia. c0m on the right. Function trimRight (s ){ If (s = null) return ""; Var whitespace = new String ("tnr "); Var str = new String (s ); If (whitespace. indexOf (str. charAt (str. length-1 ))! =-1 ){ Var I = str. length-1; While (I> = 0 & whitespace. indexOf (str. charAt (I ))! =-1 ){ I --; } Str = str. substring (0, I + 1 ); } Return str; }
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