[JavaScript] common APIs for string objects

Concat (str1, str2 ,···)

Connection string

Indexof (STR, start)

Returns the position where STR appears for the first time in the string.

 
VaRSTR = "Hello World"; Str. indexof ("Hello ");//0Str. indexof ("O", 5 );//7Str. indexof ("world ");//-1
 

Lastindexof (STR, start)

Returns the position of STR in the string.

VaRSTR = "Hello World"; Str. lastindexof ("Hello ");//0Str. lastindexof ("O", 3 );//-1Str. lastindexof ("O", 5 );//4
 

Replace (Regexp/substr, replacement)

In a string, replace some characters with other characters, or replace a string that matches the regular expression.

 
VaRSTR = "I is Allen ."; Str. Replace ("Is", "am ");//"I am Allen ."
 

Slice (START, end)

Returns a string segment.

VaRSTR = "I am Jack ."; Str. Slice (3, 7 );//"M ja"Str. Slice (3 );//"M jack ."Str. Slice (3,-3 );//"M ja"
 

Split (separator, limit)

Splits a string into substrings and returns the result as a string array.

 
VaRSTR = "Hello World"; Str. Split ("");//["Hello", "world"]Str. Split ("", 1 );//["Hello"]
 

Substr (START, lenght)

Returns a string of the specified length starting from the specified position.

VaRSTR = "How do you do? "; Str. substr (4, 2 );//"Do"Str. substr (4 );//"Do you do? "Str. substr (4, 0 );//""Str. substr (4,-1 );//""Str. substr (-3 );//"Do? "
 

Substring (START, end)

Returns the string at the specified position in the string object, including the start character, but not the end character.

 
VaRSTR = "How do you do? "; Str. substring (0, 3 );//"How"
 

Tolowercase ()

Converts a string to lowercase.

Touppercase ()

Converts a string to uppercase.

 
VaRSTR = "How do you do? "; Str. tolowercase ();//"How do you do? "Str. touppercase ();//"How do you do? "