TypeScript string object:
A TypeScript String object represents a sequence of characters.
TypeScript String Object Properties:
| Property | Description |
| constructor | It returns a reference to the String function that created the object. |
| length | It returns the length of the string. |
| prototype | It allows us to add properties and methods to an object. |
TypeScript String Object Methods:
| Method | Description |
| charAt() | It returns the character at the specified index. |
| charCodeAt() | It returns a number indicating the Unicode value of the character at the given index. |
| concat() | It combines the text of two strings and returns a new string. |
| indexOf() | It returns the index within the calling String object of the first occurrence of the specified value, or -1 if not found. |
| lastIndexOf() | It returns the index within the calling String object of the last occurrence of the specified value, or -1 if not found. |
| localeCompare() | It returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order. |
| match() | It is used to match a regular expression against a string. |
| replace() | It is used to find a match between a regular expression and a string, and to replace the matched substring with a new substring. |
| search() | It executes the search for a match between a regular expression and a specified string. |
| slice() | It extracts a section of a string and returns a new string. |
| split() | It splits a String object into an array of strings by separating the string into substrings. |
| substr() | It returns the characters in a string beginning at the specified location through the specified number of characters. |
| substring() | It returns the characters in a string between two indexes into the string. |
| toLocaleLowerCase() | The characters within a string are converted to lower case while respecting the current locale. |
| toLocaleUpperCase() | The characters within a string are converted to upper case while respecting the current locale. |
| toLowerCase() | It returns the calling string value converted to lower case. |
| toString() | It returns a string representing the specified object. |
| toUpperCase() | It returns the calling string value converted to uppercase. |
| valueOf() | It returns the primitive value of the specified object. |
How to create TypeScript string object:
- By using string literals.
- By using String() constructor.
By using number literals:
When we create a number literal browser automatically converts it to Number object.
Syntax:
var str1:string = “value”;
Example:
function stringTest(str:string):void{
console.log(str);
}
var str:string = "Sahdev";
stringTest(str);
Try it:
By using String() constructor:
We can create a TypeScript String object by using String() constructor.
Syntax:
var str1:string = new String(value);
Example:
function stringTest(str:string):void{
console.log(str);
}
var str:string = new String("Richi");
stringTest(str);