String.indexOf()の実現方式

2913 ワード


//
public
static int indexOf(byte[] source, byte[] target) { // byte[] source, byte[]target int sourceCount = source.length; int targetCount = target.length; byte first = target[0]; int max = (sourceCount - targetCount); for (int i = 0; i <= max; i++) { /* Look for first character. */ if (source[i] != first) { // source target while (++i <= max && source[i] != first) ; } /* Found first character, now look at the rest of v2 */ if (i <= max) { int j = i + 1; int end = j + targetCount - 1; for (int k = 1; j < end && source[j] == target[k]; j++, k++) // j source target +1;k target +1
                ;  
  
            if (j == end) {  
                /* Found whole string. */  
                return i;  
            }  
        }  
    }  
    return -1;  
}  

 
転載先:https://www.cnblogs.com/zhangit/p/7885810.html