Difference between NSString literals

Question

What is the difference between these two lines?

NSString * string = @\"My String\";
NSString * string = [[[NSString alloc] initWithString:@\"MyString\"] auto         


        

Answer 1

bryanmac is 100% correct in his answer. I just added an explicit example using GHUnit.

NSString creation - literal vs nonliteral.

Shows strings created in various ways if they are literal nor nonliteral.

- (void) test_stringCreation
{
    NSString *literalString = @"literalString";
    NSString *referenced = literalString;
    NSString *copy = [literalString copy];
    NSString *initWithString = [[NSString alloc] initWithString:literalString];
    NSString *initWithFormat = [[NSString alloc] initWithFormat:@"%@", literalString];

    // Testing that the memory addresses of referenced objects are the same.
    GHAssertEquals(literalString, @"literalString", @"literal");
    GHAssertEquals(referenced, @"literalString", @"literal");
    GHAssertEquals(copy, @"literalString", @"literal");
    GHAssertEquals(initWithString, @"literalString", @"literal");
    GHAssertNotEquals(initWithFormat, @"literalString",
                      @"nonliteral - referenced objects' memory addresses are \
                      different.");

    // Testing that the objects referenced are equal, i.e. isEqual: .
    GHAssertEqualObjects(literalString, @"literalString", nil);
    GHAssertEqualObjects(referenced, @"literalString", nil);
    GHAssertEqualObjects(copy, @"literalString", nil);
    GHAssertEqualObjects(initWithString, @"literalString", nil);
    GHAssertEqualObjects(initWithFormat, @"literalString", nil);

    // Testing that the strings referenced are the same, i.e. isEqualToString: .
    GHAssertEqualStrings(literalString, @"literalString", nil);
    GHAssertEqualStrings(referenced, @"literalString", nil);
    GHAssertEqualStrings(copy, @"literalString", nil);
    GHAssertEqualStrings(initWithString, @"literalString", nil);
    GHAssertEqualStrings(initWithFormat, @"literalString", nil);
}