Hand-Punched notes

String

String str = "ABC"; (String constants)

str = "Def"; (point to new String)

String str1 =new string ("Tom");

String str2 =str1;

STR1 = "Rose"; (Assigning a new string address to str1)

Output results

Char[] c= {' A ', ' B ', ' C '}

String Str3 =new string (c) (converts other types to strings)

Output

The length of the output STR3 str3.length band () is the method

STR1 = "ABC";

STR2 = "ABC";

Output = = true (= = Compare memory address)

STR1 =new String ("abc")

STR2 =new String ("abc")

Output = = False

Output (Str1.equals (STR2)); (Compare content equality)

Determine the beginning and end of a string

Output (Str1.startswith ("AB"));

Output (Str1.endwith ("C"))

Find the index value of a string

str1 = "Lkjhgfdsaqqqqqwertyuiop";

Output (Str1.indexof ("a")); (Find the index of a, no matter how many A is the first one from left to right)

Output (Str1.lastindexof ("a")); (in contrast to the above, find the first one from right to left)

Get substring

Str1.substring (Start end)

Output (str 1.charAt (1));

Replace

Str1.replace ("FD", "FD") (returns the replaced string)

Output ()

Go to Space

STR1 = "# tom #";

Output (Str1.replace ("", "")) (go to all spaces)

Output (Str1.trim ()); (Remove the front and back spaces only)

Str.replacceall ("", ""); (supports regular expressions)

Split using a specific delimiter, bar string Segmentation array
str1 = "abc#) def#) 123#) GGG";

String[] St=str.split ("#)");

Output (st.length);

Output (st[0]);

Variable character sequence

StringBuilder strb =new StringBuilder ("abc")

Strb.append ("Def")

Strb.append ("VB")

Strb.append ("AA")

Strb.append ("Def"). Append ("VB"). Append ("AA") (Another way)

StringBuffer stru =new stringbuffer ("Sdsds")

Stru.append ("SDFD")

String STR4 =stru.tostring ();

Output ()

Hand-Punched notes