如何检查字符串的内容是否为数值？

Question

我看过这个问题,但已经2岁了.是否有更好的\更容易\更新的方法来检查字符串是否具有数值.例如1或1.54或-1或-1.54等

Answer 1

bool status;
NSScanner *scanner;
NSString *testString;
double result;

scanner = [NSScanner scannerWithString:testString];
status = [scanner scanDouble:&result];
status = status && scanner.scanLocation == string.length;

如果status == YES,则字符串是完全数字.

或者@Dave从这个SO回答中指出:

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
number = [formatter numberFromString:string];
status = number != nil;

(我没有泄漏,我正在使用ARC :-))