苹果官网学习笔记-处理Foundation-NSNumber,NSString

来源：互联网发布：mysql创建存储过程例子编辑：程序博客网时间：2024/05/19 16:51

1、首先，先看一下一个简单的数据类型的封装和拆装

int a = 5;NSNumber *numberObject = [NSNumber numberWithInt:a];int b = [numberObject intValue];

快速的定义

NSNumber *myIntValue = @32;NSNumber *myDoubleValue = @3.323;NSNumber *myBollValue = @YES;NSNumber *myCharValue = @'V';NSNumber *myFloatValue = @12.5F;

2、字符串

快速创建

NSString *myString = @"sfetcde";NSString *anotherString = [NSString stringWithFormat:@"%d,%@",1,@"string"];NSString *cString = [NSString stringWithCString:"A C String" encoding:NSUTF8StringEncoding];

空字符串

NSString *emptystr = [NSString string];

拼接字符串方法

NSString *welcome = @"Welcome";NSString *beijing = [welcome stringByAppendingString:@" to Beijing"];

比较大小，可使用isEqualToString:

转换大小写：uppercaseString和lowercaseString

从开头截取字符串到指定位置 substringToIndex:

从指定位置截取字符串到末尾的方法substringFromIndex:

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