The String class in 05-java

Program Design Ideas:

The first goal is to make the input string plus a number into another string, which is equivalent to encrypting the string.

The first step is to enter a string of strings type;

The second step is to transform the string into a character array;

The third step is to Fuga each word of this array, and if it exceeds the range of 26 English letters after adding three, let the letter subtract 26-3; back to the front;

' The fourth step outputs the resulting string.

Flow chart:

SOURCE program:

import Java.util.Scanner;/** Character Encryption * Xu Haojun Date: 2016.10.26*/Public class Jiami {public staticvoidMain (string[] args) {//TODO auto-generated Method StubSystem.out.print ("Please enter a string:"); Scanner input=NewScanner (System.inch ); String a= Input.next ();//Enter a string to assign a value to a                        Charb[]=New Char[100];//defines an array of characters for storing strings                       intI//for LoopSystem.out.print ("The string after encryption is:");  for(I=0;i<a.length (); i++)//length () is used to find string lengths{B[i]=(Char) (A.charat (i));//A.charat (i) is used to return the I character in a string//and is stored in a character arrayB[i]+=3;//adds three to each character in the character array, enabling encryption                                if(b[i]-' a ' >25) {//returns the beginning of an alphabetic character when it exceeds the bounds of an alphabetic character after adding threeB[i]-=26; }                     //so that the letters that add three out of bounds returnSystem.out.print (B[i]); //Output Encrypted characters           }               }}

Program results:

The String.Equals () method of the hands-on brain:

The Equals () method in the String class is used primarily to determine whether the current string is consistent with the contents of the passed-in string.

Specific implementation:

public boolean equals (Object anobject)

{

If the same object

if (this = = AnObject)

{

return true;

}

If the passed in parameter is an instance of the string class

if (anobject instanceof String)

{

String anotherstring = (string) anobject;

int n = count;//string length

if (n = = anotherstring.count)//Compare if the lengths are equal

{

Char v1[] = value;//The character of each position

Char v2[] = Anotherstring.value;

int i = offset;

int j = Anotherstring.offset;

while (n--! = 0)//For each location comparison

{

if (v1[i++]! = v2[j++])

return false;

}

return true;

}

}

return false;

}

Some common methods of string are summarized:

Length (): Gets the string length

CharAt (): Gets the character at the specified position

GetChars (): Gets the substring from the specified position copied into the character array (it has four parameters, as described in the example)

Replace (): substring substitution

toUpperCase (), toLowerCase (): Uppercase and lowercase conversions

Trim (): Remove the Kinsoku space:

ToCharArray (): Converts a String object to a character array

The String class in 05-java