判断银行账号是否输入正确

- (BOOL)checkCardNo:(NSString*) cardNo{

intoddsum =0;//奇数求和

intevensum =0;//偶数求和

intallsum =0;

intcardNoLength = (int)[cardNolength];

intlastNum = [[cardNosubstringFromIndex:cardNoLength-1]intValue];

cardNo = [cardNosubstringToIndex:cardNoLength -1];

for(inti = cardNoLength -1; i>=1;i--) {

NSString*tmpString = [cardNosubstringWithRange:NSMakeRange(i-1,1)];

inttmpVal = [tmpStringintValue];

if(cardNoLength %2==1) {

if((i %2) ==0){

tmpVal*=2;

if(tmpVal>=10)

tmpVal -=9;

evensum += tmpVal;

}else{

oddsum += tmpVal;

}

}else{

if((i %2) ==1){

tmpVal*=2;

if(tmpVal>=10)

tmpVal -=9;

evensum += tmpVal;

}else{

oddsum += tmpVal;

}

}

}

allsum = oddsum + evensum;

allsum += lastNum;

if((allsum %10) ==0)

returnYES;

else

returnNO;

}