C 小數點格式化

1.tostring()方法

double d=12345678.2334;

console.writeline(d.tostring("f2"));

console.writeline(d.tostring("###,###.00")); //12,345,678.23

2.math.round()方法

math.round(3.44, 1); //returns 3.4.

math.round(3.45, 1); //returns 3.4.

math.round(3.46, 1); //returns 3.5.

math.round(3.445, 1); //returns 3.4.

math.round(3.455, 1); //returns 3.5.

math.round(3.465, 1); //returns 3.5.

math.round(3.450, 1); //returns 3.4.(補0是無效的)

math.round(3.4452, 2); //returns 3.45.

math.round(3.4552, 2); //returns 3.46.

math.round(3.4652, 2); //returns 3.47.

"四捨六入五考慮，五後非零就進一，五後皆零看奇偶，五前為偶應捨 去，五前為奇要進一"

短一點的口訣叫「四捨、六入、五湊偶」

3.double.parse()方法

double   d=1.12345;  

d=double.parse(d.tostring("0.00")); 

4.輸出百分號

system.globalization.numberformatinfo provider = new system.globalization.numberformatinfo();

provider.percentdecimaldigits = 2;//小數點保留幾位數.

provider.percentpositivepattern = 1;//百分號出現在何處.

double result = (double)1 / 3;//一定要用double型別.

console.writeline(result.tostring("p", provider));

或 console.writeline((result*100).tostring("#0.#0")+"%");

5.string.format()方法

string str1 = string.format("",56789); //result: 56,789.0

string str2 = string.format("",56789); //result: 56,789.00

string str3 = string.format("",56789); //result: 56,789.000

string str8 = string.format("",56789); //result: 56789.0

string str9 = string.format("",56789); //result: 56789.00

string str11 =(56789 / 100.0).tostring("#.##"); //result: 567.89

string str12 =(56789 / 100).tostring("#.##"); //result: 567

C 小數點格式化

1.tostring 方法 double d 12345678.2334 console.writeline d.tostring f2 1234.23 console.writeline d.tostring 00 12,345,678.23 2.math.round 方法 math.round ...

C 小數點格式化

1.tostring 方法 double d 12345678.2334 console.writeline d.tostring f2 console.writeline d.tostring 00 12,345,678.23 2.math.round 方法 math.round 3.44,1 r...

C 小數點格式化

1.tostring 方法 double d 12345678.2334 console.writeline d.tostring f2 console.writeline d.tostring 00 12,345,678.23 2.math.round 方法 math.round 3.44,1 r...