PHP sprintf() implements formatted output_PHP tutorial-PHP Tutorial-php.cn

PHP sprintf() implements formatted output_PHP tutorial

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Release： 2016-07-13 17:14:26

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The sprintf() function is of great use in many places. I recently wrote a WeChat automatic reply interface, which contains this piece of code.

5. An optional precision indicator is in the form of a period ('.') followed by an optional string of decimal digits, that is, how many decimal digits should be displayed as floating point numbers . When this indicator is used within a string it acts as a break point, setting a maximum character limit for the string.

The code is as follows

代码如下

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$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $keyword = trim($postObj->Content);
                $time = time();
                $textTpl = "

CreateTime>%s

0
";
$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
echo $resultStr;

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$textTpl = "

CreateTime>%s

$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);

echo $resultStr;

Many friends may not know why they write it like this after reading it. What does the %S behind it mean? I will get into the topic below

Grammar

string sprintf ( string $format [, mixed $args [, mixed $... ]] )

Parameter Description

format required. Convert format.
args optional. Specifies parameters to be inserted into the format string at % symbols.

Description

The argument format string is composed of zero or more directives: normal characters (except %) will be copied directly to the result, conversion indicators, each result takes its own argument. This applies to sprintf() and printf() .

The format parameter is the format of the conversion, starting with the percent sign ("%") and ending with the conversion character. Possible format values below:

1. An optional sign indicator forces a sign (- or +) to be used on a number. By default, only the – sign is used on a number if it is a negative value. This indicator also forces positive numbers to be appended with a + sign.

2. An optional padding indicator is what character will be used to pad the result to the correct string length. This may be a blank character or a zero character. Blanks are padded by default. A replacement can be specified Fill characters are prefixed by a single quote (').

3. An optional alignment indicator says whether the result should be left-aligned or right-aligned. The default is right-aligned; a - character here will make it left-aligned.

4. An optional number, a width indicator that says how many characters (minimum) this conversion should result in.

6. A type indicator says what type the parameter data should be treated as. Possible types: % – Returns the percent symbol b – Binary number c – Character according to ASCII value d – signed decimal number e – scientific notation (e.g. 1.5e+3) E – scientific notation (e.g. 1.2E+2). (capital letter) u – unsigned decimal number f – floating point number (local settings aware) F – floating point number (not local settings aware) g – shorter of %e and %f. G – shorter of %E and %f. o – Octal number s – string x – hexadecimal number (lowercase letter) X – Hexadecimal number (capital letter) Arguments arg1, arg2, agr++, etc. are inserted into the main string at the percent sign (%) symbol. This function is executed step by step. At the first % sign, arg1 is inserted, at the second % sign, arg2, and so on.