Native JavaScript techniques collected 100 (I) (1)

1. Native JavaScript implements String Length Truncation

 
 

  
  
function cutstr(str, len) { 
  
  
    var temp; 
  
  
    var icount = 0; 
  
  
    var patrn = /[^\x00-\xff]/; 
  
  
    var strre = ""; 
  
  
    for (var i = 0; i < str.length; i++) { 
  
  
        if (icount < len - 1) { 
  
  
            temp = str.substr(i, 1); 
  
  
            if (patrn.exec(temp) == null) { 
  
  
                icount = icount + 1 
  
  
            } else { 
  
  
                icount = icount + 2 
  
  
            } 
  
  
            strre += temp 
  
  
        } else { 
  
  
            break 
  
  
        } 
  
  
    } 
  
  
    return strre + "..." 
  
  
} 
 
 

2. Obtain the domain name host using native JavaScript

 
 

  
  
function getHost(url) { 
  
  
    var host = "null"; 
  
  
    if(typeof url == "undefined"|| null == url) { 
  
  
        url = window.location.href; 
  
  
    } 
  
  
    var regex = /^\w+\:\/\/([^\/]*).*/; 
  
  
    var match = url.match(regex); 
  
  
    if(typeof match != "undefined" && null != match) { 
  
  
        host = match[1]; 
  
  
    } 
  
  
    return host; 
  
  
} 
 
 

3. Use native JavaScript to clear spaces

 
 

  
  
String.prototype.trim = function() { 
  
  
    var reExtraSpace = /^\s*(.*?)\s+$/; 
  
  
    return this.replace(reExtraSpace, "$1") 
  
  
} 
 
 

4. Replace all native JavaScript

 
 

  
  
String.prototype.replaceAll = function(s1, s2) { 
  
  
    return this.replace(new RegExp(s1, "gm"), s2) 
  
  
} 
 
 

5. Native JavaScript escape html tags

 
 

  
  
function HtmlEncode(text) { 
  
  
    return text.replace(/&/g, '&').replace(/\"/g, '"').replace(/</g, '<').replace(/>/g, '>') 
  
  
} 
 
 

7. Native JavaScript time and date format conversion

 
 

  
  
Date. prototype. Format = function (formatStr ){
  
  
Var str = formatStr;
  
  
Var Week = ['day', 'yi', '2', '3', '4', '5', '6'];
  
  
Str = str. replace (/yyyy | YYYY/, this. getFullYear ());
  
  
Str = str. replace (/yy | YY/, (this. getYear () % 100)> 9? (This. getYear () % 100). toString (): '0' + (this. getYear () % 100 ));
  
  
Str = str. replace (/MM/, (this. getMonth () + 1)> 9? (This. getMonth () + 1). toString (): '0' + (this. getMonth () + 1 ));
  
  
Str = str. replace (/M/g, (this. getMonth () + 1 ));
  
  
Str = str. replace (/w | W/g, Week [this. getDay ()]);
  
  
Str = str. replace (/dd | DD/, this. getDate ()> 9? This. getDate (). toString (): '0' + this. getDate ());
  
  
Str = str. replace (/d | D/g, this. getDate ());
  
  
Str = str. replace (/hh | HH/, this. getHours ()> 9? This. getHours (). toString (): '0' + this. getHours ());
  
  
Str = str. replace (/h | H/g, this. getHours ());
  
  
Str = str. replace (/mm/, this. getMinutes ()> 9? This. getMinutes (). toString (): '0' + this. getMinutes ());
  
  
Str = str. replace (/m/g, this. getMinutes ());
  
  
Str = str. replace (/ss | SS/, this. getSeconds ()> 9? This. getSeconds (). toString (): '0' + this. getSeconds ());
  
  
Str = str. replace (/s | S/g, this. getSeconds ());
  
  
Return str
  
  
}
 
 

8. Native JavaScript checks whether the data type is Numeric

 
 

  
  
function isDigit(value) { 
  
  
    var patrn = /^[0-9]*$/; 
  
  
    if (patrn.exec(value) == null || value == "") { 
  
  
        return false 
  
  
    } else { 
  
  
        return true 
  
  
    } 
  
  
} 
 
 

9. Set the cookie value in native JavaScript

 
 

  
  
function setCookie(name, value, Hours) { 
  
  
    var d = new Date(); 
  
  
    var offset = 8; 
  
  
    var utc = d.getTime() + (d.getTimezoneOffset() * 60000); 
  
  
    var nd = utc + (3600000 * offset); 
  
  
    var exp = new Date(nd); 
  
  
    exp.setTime(exp.getTime() + Hours * 60 * 60 * 1000); 
  
  
    document.cookie = name + "=" + escape(value) + ";path=/;expires=" + exp.toGMTString() + ";domain=360doc.com;" 
  
  
} 
 
 

10. Obtain the cookie value using native JavaScript.

 
 

  
  
function getCookie(name) { 
  
  
    var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)")); 
  
  
    if (arr != null) return unescape(arr[2]); 
  
  
    return null 
  
  
} 
 
 

11. Adding native JavaScript to favorites

 
 

  
  
Function AddFavorite (sURL, sTitle ){
  
  
Try {
  
  
Window. external. addFavorite (sURL, sTitle)
  
  
} Catch (e ){
  
  
Try {
  
  
Window. sidebar. addPanel (sTitle, sURL ,"")
  
  
} Catch (e ){
  
  
Alert ("failed to add to favorites, please add with Ctrl + D ")
  
  
}
  
  
}
  
  
}
 
 

12. Set native JavaScript as the homepage

 
 

  
  
Function setHomepage (){
  
  
If (document. all ){
  
  
Document. body. style. behavior = 'url (# default # homepage )';
  
  
Document. body. setHomePage ('HTTP: // www.jq-school.com ')
  
  
} Else if (window. sidebar ){
  
  
If (window. netscape ){
  
  
Try {
  
  
Netscape. security. PrivilegeManager. enablePrivilege ("UniversalXPConnect ")
  
  
} Catch (e ){
  
  
Alert ("this operation is rejected by the browser. To enable this function, enter about: config in the address bar, and set the value of signed. applets. codebase_principal_support to true ")
  
  
}
  
  
}
  
  
Var prefs = Components. classes ['@ mozilla.org/preferences-service%1'}.getservice (Components. interfaces. nsIPrefBranch );
  
  
Prefs. setCharPref ('browser. startup. homepage', 'HTTP: // www.jq-school.com ')
  
  
}
  
  
}