OC: Some usages of variable string nsmutablestring

NSString is an immutable string, so the method call does not modify the original string, but instead establishes a copy of the original string and modifies the contents of the copy.

Nsmutablestring is a subclass of NSString and can use all of its methods.

1.NSMutableString provides a way to attach strings.

You can use appendstring or AppendFormat to manipulate variable strings:

-(void) appendString: (NSString *) string;

-(void) AppendFormat: (NSString *) string;

AppendString accepts the parameter string and then copies it to the end of the accepted object.

Similar to AppendFormat, he appends the formatted string to the end of the accepted object, rather than creating a new object.

2. inserting a string

Nsmutablestring*str=[[nsmutablestring alloc ]initwithformat: @"abc"];

[str insertstring: @"xyz" atindex:2];

3. Replacing Strings

[str replacecharactersinrange:nsmakerange(0, 3) withstring: @"123"];     

4. Delete a string

[string19 deletecharactersinrange:nsmakerange(0, 3)];

OC: Some usages of variable string nsmutablestring