JavaScript: el objeto Strings
los Stringobject te permite trabajar con una serie de personajes; envuelve el tipo de datos primitivo de cadena de Javascript con varios métodos auxiliares.
Como JavaScript convierte automáticamente entre primitivas de cadena y objetos de cadena, puede llamar a cualquiera de los métodos auxiliares del objeto String en una primitiva de cadena.
Sintaxis
Utilice la siguiente sintaxis para crear un objeto String:
var val = new String(string);
los String El parámetro es una serie de caracteres que se ha codificado correctamente.
Propiedades de cadena
Aquí hay una lista de las propiedades del objeto String y su descripción.
No Señor. | Descripción de propiedad |
---|---|
1 | constructor Returns a reference to the String function that created the object. |
2 | length Returns the length of the string. |
3 | prototype The prototype property allows you to add properties and methods to an object. |
In the following sections, we will have a few examples to demonstrate the usage of String properties.
String Methods
Here is a list of the methods available in String object along with their description.
Sr.No. | Method & Description |
---|---|
1 | charAt() Returns the character at the specified index. |
2 | charCodeAt() Returns a number indicating the Unicode value of the character at the given index. |
3 | concat() Combines the text of two strings and returns a new string. |
4 | indexOf() Returns the index within the calling String object of the first occurrence of the specified value, or -1 if not found. |
5 | lastIndexOf() Returns the index within the calling String object of the last occurrence of the specified value, or -1 if not found. |
6 | localeCompare() Returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order. |
7 | match() Used to match a regular expression against a string. |
8 | replace() Used to find a match between a regular expression and a string, and to replace the matched substring with a new substring. |
9 | search() Executes the search for a match between a regular expression and a specified string. |
10 | slice() Extracts a section of a string and returns a new string. |
11 | split() Splits a String object into an array of strings by separating the string into substrings. |
12 | substr() Returns the characters in a string beginning at the specified location through the specified number of characters. |
13 | substring() Returns the characters in a string between two indexes into the string. |
14 | toLocaleLowerCase() The characters within a string are converted to lower case while respecting the current locale. |
15 | toLocaleUpperCase() The characters within a string are converted to upper case while respecting the current locale. |
16 | toLowerCase() Returns the calling string value converted to lower case. |
17 | toString() Returns a string representing the specified object. |
18 | toUpperCase() Returns the calling string value converted to uppercase. |
19 | valueOf() Returns the primitive value of the specified object. |
String HTML Wrappers
Here is a list of the methods that return a copy of the string wrapped inside an appropriate HTML tag.
Sr.No. | Method & Description |
---|---|
1 | anchor() Creates an HTML anchor that is used as a hypertext target. |
2 | big() Creates a string to be displayed in a big font as if it were in a <big> tag. |
3 | blink() Creates a string to blink as if it were in a <blink> tag. |
4 | bold() Creates a string to be displayed as bold as if it were in a <b> tag. |
5 | fixed() Causes a string to be displayed in fixed-pitch font as if it were in a <tt> tag |
6 | fontcolor() Causes a string to be displayed in the specified color as if it were in a <font color="color"> tag. |
7 | fontsize() Causes a string to be displayed in the specified font size as if it were in a <font size="size"> tag. |
8 | italics() Causes a string to be italic, as if it were in an <i> tag. |
9 | link() Creates an HTML hypertext link that requests another URL. |
10 | small() Causes a string to be displayed in a small font, as if it were in a <small> tag. |
11 | strike() Causes a string to be displayed as struck-out text, as if it were in a <strike> tag. |
12 | sub() Causes a string to be displayed as a subscript, as if it were in a <sub> tag |
13 | sup() Causes a string to be displayed as a superscript, as if it were in a <sup> tag |
In the following sections, we will have a few examples to demonstrate the usage of String methods.