Microsoft AJAX Library Cheat Sheet（6）：String和Object类型的扩展

本文为翻译，英文原版的Cheat Sheet（PDF版本）在此下载：http://aspnetresources.com/downloads/ms_ajax_library_cheat_sheets1.zip

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注：标注有[S]的为静态方法，无须实例化对象即可使用。

 

String.endsWith (suffix)

判断该String是否以指定的后缀结束。

var isTxt = myString.endsWith ("some_file.txt", ".txt");

// isTxt = true

 

[S] String.format (format, args)

将该String中的各个格式化项用相应的参数值替代。args可以为单一的Object，或是一个包含多个项的Array。

var user = {

    FirstName: 'John',

    LastName : 'Doe',

    DOB: new Date (1975, 1, 17) };

var label = String.format ("User name: {0} {1}, born {2:d}",

    user.FirstName, user.LastName, user.DOB));

// label = "User name: John Doe, born 02/17/1975"

 

[S] String.localeFormat (format, args)

功能与String.format (format, args)类似，不过格式化时与区域设定相关。

 

String.startsWith (prefix)

判断该String是否以指定的前缀开始。请参考String.endsWith (suffix)。

 

String.trim ()

返回一个原String的拷贝，但将原String开头和结尾部分的所有空白字符（例如空格或Tab）都移除。

var myString = "   A string   ";

myString = myString.trim();

// myString = "A string"

 

String.trimEnd ()

返回一个原String的拷贝，但将原String结尾部分的所有空白字符（例如空格或Tab）都移除。

var myString = "A string   ";

myString = myString.trim();

// myString = "A string"

 

String.trimStart ()

返回一个原String的拷贝，但将原String开头部分的所有空白字符（例如空格或Tab）都移除。

var myString = "   A string";

myString = myString.trim();

// myString = "A string"

 

[S] Object.getType (instance)

返回指定对象的类型，请参考Object.getTypeName (instance)。

 

[S] Object.getTypeName (instance)

返回一个表示对象在运行时的完全限定类型的字符串。

Type.registerNamespace("Samples");

// Define and register a Samples.Rectangle class.

Samples.Rectangle = function(width, height) {

    this._width = width;

    this._height = height;

}

Samples.Rectangle.registerClass("Samples.Rectangle");

var a = new Samples.Rectangle(200, 100);

var name = Object.getTypeName(a);

var type = Object.getType (a);

Sys.Debug.trace ("The type name of object \"a\" is: " + name);

Sys.Debug.traceDump (type);

/* The result is:

    The type name of object "a" is: Samples.Rectangle

    traceDump {Function}

    prototype {Samples.Rectangle}

        __typeName: Samples.Rectangle

        __class: true

*/