PHP integer part padding

问题:

I need to pad the integer part with 0, the integer part must be at least 2 characters

str_pad( 2    ,2,"0",STR_PAD_LEFT);// 02 -> works
str_pad( 22   ,2,"0",STR_PAD_LEFT);// 22 -> works
str_pad( 222  ,2,"0",STR_PAD_LEFT);// 222-> works
str_pad( 2.   ,2,"0",STR_PAD_LEFT);// 2. -> fails -> 02. or 02
str_pad( 2.11 ,2,"0",STR_PAD_LEFT);// 2.11-> fails -> 02.11

Is there simple code for that?

If possible the same in Java please

double x=2.11;
String.format("%02d%s", (int) x, String.valueOf(x-(int) x).substring(1))

is not only ugly but prints 02.10999999999999988

edit for Java: Java integer part padding

回答1:

You can also use printf() functions to pad the integer :

Something like (codepad):

<?php

function pad($n) {
    $n = explode('.', (string)$n);

    if (2 === count($n)) {
        return sprintf("%02d.%d\n", $n[0], $n[1]);    
    }

    return sprintf("%02d\n", $n[0]);    
}

foreach (array(2, 22, 222, 2., 2.11) as $num) {
    echo pad($num);
}

// returns 02, 22, 222, 02, 02.11

回答2:

No, there is no simple way.

function padIntegerPart($n, $len) {
    $intPart = (int)$n;

    return str_repeat('0', max(0, $len - 1 - floor(log($intPart, 10)))) . $n;
}

回答3:

A fast solution: http://codepad.org/EXcbqGos

$num = 2.11;
echo str_pad( floor($num) ,2,"0",STR_PAD_LEFT).substr($num-floor($num), 1);

It will only work for non-negative numbers.

回答4:

If the output you're looking for is 02.11, then try sprintf():

sprintf("%05.2f", 02.11); // Output: 02.11
           ^ ^--- float precision
           |--- total string length

sprintf("%07.2f", 02.11); // Output: 0002.11

Links that may help are:

http://us2.php.net/sprintf

Extra leading zeros when printing float using printf?

回答5:

Another one :

function my_str_pad ($input ,$pad_length, $pad_string) {
    $pad_length += strlen($input) - strlen(intval($input));

    return str_pad($input, $pad_length, $pad_string, STR_PAD_LEFT);
}

The following test :

str_pad(2., 2, "0", STR_PAD_LEFT);// 2. -> fails -> 02. or 02

Fails because str_pad is working on a string, but you entered a number with a decimal but no decimal part so it is considered as an integer. If you want to keep the '.' use the following instead :

str_pad("2.", 2, "0" , STR_PAD_LEFT);// 2. -> works