如何检查NSString是否为数字 [英] How to check if NSString is numeric or not

问题描述

可能重复:
iphone如何检查字符串是否仅为数字

Possible Duplicate:
iphone how to check that a string is numeric only

我有一个NSString，然后我要检查字符串是否为数字.

I have one NSString, then i want check the string is number or not.

我的意思是

NSString *val = @"5555" ;

if(val isNumber ){
  return true;
}else{
  retun false;
}

如何在Objective C中做到这一点?

How can I do this in Objective C?

推荐答案

使用[NSNumberFormatter numberFromString: s].如果指定的字符串不是数字，则返回nil.您可以配置NSNumberFormatter为您的特定方案定义数字".

Use [NSNumberFormatter numberFromString: s]. It returns nil if the specified string is non-numeric. You can configure the NSNumberFormatter to define "numeric" for your particular scenario.

#import <Foundation/Foundation.h>

int
main(int argc, char* argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSLocale *l_en = [[NSLocale alloc] initWithLocaleIdentifier: @"en_US"];
    NSLocale *l_de = [[NSLocale alloc] initWithLocaleIdentifier: @"de_DE"];
    NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
    [f setLocale: l_en];

    NSLog(@"returned: %@", [f numberFromString: @"1.234"]);

    [f setAllowsFloats: NO];
    NSLog(@"returned: %@", [f numberFromString: @"1.234"]);

    [f setAllowsFloats: YES];
    NSLog(@"returned: %@", [f numberFromString: @"1,234"]);

    [f setLocale: l_de];
    NSLog(@"returned: %@", [f numberFromString: @"1,234"]);

    [l_en release];
    [l_de release];
    [f release];
    [pool release];
}

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