left triangle in not use inbuild method in java

`public class lefttrangle {

public static void main(String[] args) {
    for(int i=0;i<=4;i++){

        for(int j=0;j<=i;j++)
        {
            System.out.print(j);
        }
        System.out.println();
    }

}

}
`output :-

0
01
012
0123
01234