String arrays methods and if statement-CodePudding

here, it gives b's element as null rather than storing array a's value. Basically, I can't go inside the if statement

public class Dil {
    public static void main(String[] args) {
        String s = "is2 sentence4 This1 a3";
        String a[]=s.split(" ");
        String b[]=new String[a.length];
        System.out.println(Arrays.toString(a));
        for(int i=1;i<a.length;i  ){
            for(int j=0;j<a.length-1;j  ){
                if(a[j].charAt(a[j].length()-1)==i){
                    b[i-1]=a[j];
                    break;
                }

            }
        }
        System.out.println(Arrays.toString(b));
    }
}

CodePudding user response：

I think thats more like what u wanted:

public class Dil {
    public static void main(String[] args) {
        String s = "is2 sentence4 This1 a3";
        String a[]=s.split(" ");
        String b[]=new String[a.length];
        System.out.println(Arrays.toString(a));
        for(int i=1;i<a.length;i  ){
            for(int j=0;j<a.length-1;j  ){
                if(a[j].charAt(a[j].length()-1)==((char)(i   '0'))){
                    b[i-1]=a[j];
                    break;
                }

            }
        }
        System.out.println(Arrays.toString(b));
    }
}

But that just works if 0<=i<=9

CodePudding user response：

You have two unrelated problems.

here, it gives b's element as null rather than storing array a's value.

That's because your instantiating a new and empty array, only providing to it the size of array a (not the values!), with:

String b[] = new String[a.length];

If you want to copy an array, better do:

String[] a = new String[] {/*..your array..*/};
String[] b = new String[a.length];
System.arraycopy(a, 0, b, 0, a.length);

String[] b = Arrays.copyOf(a, a.length);

Basically, I can't go inside the if statement

Variable of type char, indeed can store a number, as under the hood, chars are represented as ASCII codes.

Therefore, your:

(a[j].charAt(a[j].length()-1)==i)

would only evaluate to true, when i will be equal to ASCII code of the char in question; however, characters represented with [0; 31] codes, are non-printable ones, which, most likely, will not be include in your strings and hence - your if's condition will not evaluate to true.