定义 说明 %@ Objective-C object, printed as the string returned by descriptionWithLocale: if available, or description otherwise. Also works with CFTypeRef objects, returning the result of the CFCopyDescription function. %% ‘%’ character %d, %D, %i Signe
一,python中的in,和not in python中in的作用是检测或查找,例如: c = ‘你好大号胡覅但是啊飞碟说’ b = ‘你好’ print(b in c ) 结果: True c = ‘你好大号胡覅但是啊飞碟说’ b = ‘大好’ print(b in c ) 结果; Flase 检测的时候是从头开始一次检测,并且按照输入的内容查 而not in则是类似的方式,in的否定,再进行判断,于上相同. 二,运算符运用 1.基本运算符 与数学中的加减乘除类似,在基本符号的运用上增加了可让
Java中数字的格式化输出 double d = 345.678; String s = "hello!"; int i = 1234; //"%"表示进行格式化输出,"%"之后的内容为格式的定义. System.out.printf("%f",d);//"f"表示格式化输出浮点数. System.out.printf("%9.2f",d);//"9.2"中的9表示输