java printf的一些常用的打印格式总结

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package baseDemo1;/** * printf的一些常用的打印格式总结 * @author chen 2014年11月27日16:26:07 * */public class PrintfDemo {public static void main(String[] args) {String str = "I like data mining";int i = 1234;double d = 3.14159265358979;float f1 = -0.123456f;float f2 = 0.123456f;System.out.printf("1，str = %20s\n", str); //String类型System.out.printf("2，i = %d\n", i); //int类型System.out.printf("3，d = %f\n", d); //double类型，默认小数是6位/*10表示输出的长度，从右至左所有数字和字符的长度，如果字符没有10个，则左边补上空格；若大于10个，字符全部打印出来*/System.out.printf("4，d = %10f\n", d); System.out.printf("5，d = %.2f\n", d); //.2表示小数点的位数System.out.printf("6，f1 = %f\n", f1); //flaot类型System.out.printf("7，f2 = %f\n", f2); //float类型，正数的时候，无符号System.out.printf("8，f2 = %+f\n", f2); //float类型，正数的时候，显示数字的符号System.out.printf("9，%%"); //打印“%”，只写一个%会报错System.out.println();System.out.println("");PrintfDemo.nineNine();}/** * Description:打印九九乘法表 * */static void nineNine(){for (int i = 1; i < 10; i++){for (int j = 1; j <= i; j++){System.out.printf("%d*%d =%2d ", i, j, i*j); }System.out.println();}}}

打印结果：

1，str =   I like data mining2，i = 12343，d = 3.1415934，d =   3.1415935，d = 3.146，f1 = -0.1234567，f2 = 0.1234568，f2 = +0.1234569，%1*1 = 1 2*1 = 2 2*2 = 4 3*1 = 3 3*2 = 6 3*3 = 9 4*1 = 4 4*2 = 8 4*3 =12 4*4 =16 5*1 = 5 5*2 =10 5*3 =15 5*4 =20 5*5 =25 6*1 = 6 6*2 =12 6*3 =18 6*4 =24 6*5 =30 6*6 =36 7*1 = 7 7*2 =14 7*3 =21 7*4 =28 7*5 =35 7*6 =42 7*7 =49 8*1 = 8 8*2 =16 8*3 =24 8*4 =32 8*5 =40 8*6 =48 8*7 =56 8*8 =64 9*1 = 9 9*2 =18 9*3 =27 9*4 =36 9*5 =45 9*6 =54 9*7 =63 9*8 =72 9*9 =81

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