java的atoi,java版atoi

public class atoi {

public static void main(String args[]) {

char[] c = { '1', '0', '9', '4' };

int i = atoi(c);

System.out.print(i);

}

private static int atoi(char[] c) {

if (containsOthers(c))

return -1;

int result = 0;

for (int i = 0; i < c.length; i++) {

result = result + (c[i] - '0')

* (int) (Math.pow(10, c.length - i - 1));

}

return result;

// return c[2]-'0'+(c[1]-'0')*10+(c[0]-'0')*100;

}

private static boolean containsOthers(char[] c) {

for (int i = 0; i < c.length; i++) {

if (c[i] - '0' < 0 || c[i] - '0' > 9)

return true;

}

return false;

}

}