如何在不使用库 function 的情况下删除 java 中字符串之间的空格？

Question

I am getting the solution is as follows

class StringCheck
{
    public static void main (String[] args) 
    {   
        String str="Hello world I am here";
        String r;

        System.out.println(str);    
        r = str.replaceAll(" ","");
        System.out.println(r);  
    }
}
OUTPUT: HelloworldIamhere

but I don't want to use a library function ie str.replaceAll(), Can anyone help me with the program.I want same output as I got using library function

Answer 1

What I understood from your question is you don't want to use str.replaceAll() function. So possible alternative is following. Please refer more details Removing whitespace from strings in Java

import java.util.*;

public class StringCheck {
    public static void main(String[] args) {
        String str = "Hello world I am here";
        String r = "";

        Scanner sc = new Scanner(str);

        while(sc.hasNext()) {
            r += sc.next();
        }
        System.out.println(r);
    }
}

Answer 2

Well as you do not want to keep the value just loop and print

    String str="Hello world I am here";

    for (char c : str.toCharArray()) {
        if (c != ' ')
            System.out.print(c);
    }

output

HelloworldIamhere

Of course if you wanted to keep this new String then use a StringBuilder and append the char instead of/and print it

Answer 3

Iterate each char in str .

If it is not equal ' ', append it to your result string r .

But why would you want to do it without using library functions?

Answer 4

public class Removespaces {

    public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     String s = sc.nextLine();
     char[] ch = s.toCharArray();
     String s1 = "";
     for(int i=0;i<ch.length;i++){
         if(s.charAt(i)==' ')
         {
                 continue;
         }else{
             s1 = s1 + s.charAt(i);
         }
     }
     System.out.println(s1);
    }
}

Answer 5

Hey I have solution for that question you can have this way. I didn't use in-build function

public class RemoveSpace {

 public static void main(String[] args) {
    String str="Abd is a good guy";
    
    char[] a=str.toCharArray();
    System.out.println(a);
    int size=a.length;
    for(int i=0; i<size;i++)
    {
        if(a[i]==32)
        {
            for(int j=i;j<size-1;j++)
            {
                a[j]=a[j+1];
            }
            size--;
            
        }
        
    }
    for(int i=0; i<size; i++)
    {
    System.out.print(a[i]);
    }
}}

Answer 6

String s = "Hello world I am here";
StringBuilder sb = new StringBuilder();
for (char c : s.toCharArray()) {
    if (c != ' ') {
        sb.append(c);
    }
}
System.out.println(sb.toString());