IOStream

D3.format()

 Dec 4, 2015   D3      js format

3 minute read

总结一下format函数的使用

Numbers

d3.format(specifier):Returns a new format function with the given string specifier

[​[fill]align][sign][symbol][0][width][,][.precision][type]

  1. fill:填充字符，除了’{‘和’}’外，其他的都可以使用，通常与后面的align(对齐),width(长度)合用 d3.format(‘4<6’)(100) => ‘444100’

  2. sign:正负号位，可以使plus(+),mins(-),以及space(‘ ‘),space 表示正数时不显示，负数时显示符号

  3. symbol: 符号位，有(“$”)和base(“#”)

  4. 0表示用0补齐

  5. ’,’用于数字的以千分位

  6. precision,精度

d3.round(x[,n]):Returns the value x rounded to n digits after the decimal point. If n is omitted, it defaults to zero. The result is a number.n表示小数点后保留几位

Time

  • %a abbreviated weekday name.
  • %A full weekday name.
  • %b abbreviated month name.
  • %B full month name.
  • %c date and time, as “%a %b %e %H:%M:%S %Y”.
  • %d zero-padded day of the month as a decimal number [01,31].
  • %e space-padded day of the month as a decimal number [ 1,31]; equivalent to %_d.
  • %H hour (24-hour clock) as a decimal number [00,23].
  • %I hour (12-hour clock) as a decimal number [01,12].
  • %j day of the year as a decimal number [001,366].
  • %m month as a decimal number [01,12].
  • %M minute as a decimal number [00,59].
  • %L milliseconds as a decimal number [000, 999].
  • %p either AM or PM.
  • %S second as a decimal number [00,61].
  • %U week number of the year (Sunday as the first day of the week) as a decimal number [00,53].
  • %w weekday as a decimal number [0(Sunday),6].
  • %W week number of the year (Monday as the first day of the week) as a decimal number [00,53].
  • %x date, as “%m/%d/%Y”.
  • %X time, as “%H:%M:%S”.
  • %y year without century as a decimal number [00,99].
  • %Y year with century as a decimal number.
  • %Z time zone offset, such as “-0700”.
  • %% a literal “%” character.
d3.round(1.23); // 1
d3.round(1.23, 1); // 1.2
d3.round(1.25, 1); // 1.3
d3.round(12.5, 0); // 13
d3.round(12, -1); // 10

d3.format(",")(1000000);    //"1,000,000"
d3.format(",")(1010101);    //"1,010,101"
d3.format(",.4g")(1010101); //"1.010e+6"

d3.format("8")(1);      //"       1"
d3.format("8,.2f")(1);  //"    1.00"
d3.format("8g")(1e6);   //" 1000000"

d3.format("8")(1234);          //"    1234"
d3.format("08")(1234);         //"00001234"
d3.format("08.2f")(123.456);   //"00123.46"
d3.format("08.3f")(123.456);   //"0123.456"

d3.format("09,")(123456);      //"0,123,456"
d3.format("$,")(1250);         //"$1,250"
d3.format("$,.2f")(1250);      //"$1,250.00"

d3.format("0b")(125);  //"1111101"
d3.format("0o")(125);  //"175"
d3.format("0x")(125);  //"7d"

d3.format("+")(125);  //"+125"
d3.format("+")(-125); //"-125"
d3.format("-")(125);  //"125"
d3.format("-")(-125); //"-125"
d3.format(" ")(125);  //" 125"
d3.format(" ")(-125); //"-125"

d3.format("4>8")(1); //"44444441"
d3.format("4^8")(1); //"44441444"
d3.format("4<8")(1); //"14444444"