objective-c NSString 是整数吗？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/565696/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
NSString is integer?
提问by Carlos Barbosa
How to check if the content of a NSString is an integer value? Is there any readily available way?
如何检查 NSString 的内容是否为整数值？有没有现成的方法？
There got to be some better way then doing something like this:
必须有一些更好的方法然后做这样的事情：
- (BOOL)isInteger:(NSString *)toCheck {
if([toCheck intValue] != 0) {
return true;
} else if([toCheck isEqualToString:@"0"]) {
return true;
} else {
return false;
}
}
回答by Stephen Darlington
You could use the -intValueor -integerValuemethods. Returns zero if the string doesn't start with an integer, which is a bit of a shame as zero is a valid value for an integer.
您可以使用-intValueor-integerValue方法。如果字符串不是以整数开头，则返回零，这有点遗憾，因为零是整数的有效值。
A better option might be to use [NSScanner scanInt:]which returns a BOOLindicating whether or not it found a suitable value.
更好的选择可能是使用[NSScanner scanInt:]which 返回一个BOOL指示它是否找到合适的值。
回答by Steven Green
Something like this:
像这样的东西：
NSScanner* scan = [NSScanner scannerWithString:toCheck];
int val;
return [scan scanInt:&val] && [scan isAtEnd];
回答by coco
Building on an answerfrom @kevbo, this will check for integers >= 0:
基于@kevbo的回答，这将检查整数 >= 0：
if (fooString.length <= 0 || [fooString rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]].location != NSNotFound) {
NSLog(@"This is not a positive integer");
}
A swift version of the above:
上面的一个快速版本：
func getPositive(incoming: String) -> String {
if (incoming.characters.count <= 0) || (incoming.rangeOfCharacterFromSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet) != nil) {
return "This is NOT a positive integer"
}
return "YES! +ve integer"
}
回答by TtheTank
Do not forget numbers with decimal point!!!
不要忘记带小数点的数字！！！
NSMutableCharacterSet *carSet = [NSMutableCharacterSet characterSetWithCharactersInString:@"0123456789."];
BOOL isNumber = [[subBoldText stringByTrimmingCharactersInSet:carSet] isEqualToString:@""];
回答by black_pearl
func getPositive(input: String) -> String {
if (input.count <= 0) || (input.rangeOfCharacter(from: NSCharacterSet.decimalDigits.inverted) != nil) {
return "This is NOT a positive integer"
}
return "YES! integer"
}
Update @coco's answer for Swift 5
更新@coco 对 Swift 5 的回答
