输出格式化的字符串:
<?php
$number = 9;
$str = "Beijing";
printf("There are %u million bicycles in %s.",$number,$str);
?>
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printf() 函数输出格式化字符串。
arg1、arg2、++ 参数将插入到主字符串中的百分号 (%) 处。此功能有效"step-by-step"。在第一个 % 符号处插入 arg1,在第二个 % 符号处插入 arg2,依此类推。
笔记:如果 % 符号多于参数,则必须使用占位符。占位符插入到 % 符号之后,由参数数字和 "\$" 组成。参见示例二。
提示:相关功能:sprintf(),vprintf(),vsprintf(),fprintf()和vfprintf()
printf(
format,arg1,arg2,arg++)
Parameter | Description |
---|---|
format | Required. Specifies the string and how to format the variables in it. Possible format values:
Additional format values. These are placed between the % and the letter (example %.2f):
Note: If multiple additional format values are used, they must be in the same order as above. |
arg1 | Required. The argument to be inserted at the first %-sign in the format string |
arg2 | Optional. The argument to be inserted at the second %-sign in the format string |
arg++ | Optional. The argument to be inserted at the third, fourth, etc. %-sign in the format string |
返回值: | 返回输出字符串的长度 |
---|---|
PHP 版本: | 4+ |
占位符的使用:
<?php
$number = 123;
printf("With 2 decimals: %1\$.2f
<br>With no decimals: %1\$u",$number);
?>
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所有可能的格式值的演示:
<?php
$num1 = 123456789;
$num2 = -123456789;
$char = 50; // The ASCII Character 50 is 2
// Note: The format value "%%" returns a percent sign
printf("%%b = %b <br>",$num1); // Binary number
printf("%%c = %c <br>",$char); // The ASCII Character
printf("%%d = %d <br>",$num1); // Signed decimal number
printf("%%d = %d <br>",$num2); // Signed decimal number
printf("%%e = %e <br>",$num1); // Scientific notation (lowercase)
printf("%%E = %E <br>",$num1); // Scientific notation (uppercase)
printf("%%u = %u <br>",$num1); // Unsigned decimal number (positive)
printf("%%u = %u <br>",$num2); // Unsigned decimal number (negative)
printf("%%f = %f <br>",$num1); // Floating-point number (local settings aware)
printf("%%F = %F <br>",$num1); // Floating-point number (not local settings aware)
printf("%%g = %g <br>",$num1); // Shorter of %e and %f
printf("%%G = %G <br>",$num1); // Shorter of %E and %f
printf("%%o = %o <br>",$num1); // Octal number
printf("%%s = %s <br>",$num1); // String
printf("%%x = %x <br>",$num1); // Hexadecimal number (lowercase)
printf("%%X = %X <br>",$num1); // Hexadecimal number (uppercase)
printf("%%+d = %+d <br>",$num1); // Sign specifier (positive)
printf("%%+d = %+d <br>",$num2); // Sign specifier (negative)
?>
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字符串说明符的演示:
<?php
$str1 = "Hello";
$str2 = "Hello world!";
printf("[%s]<br>",$str1);
printf("[%8s]<br>",$str1);
printf("[%-8s]<br>",$str1);
printf("[%08s]<br>",$str1);
printf("[%'*8s]<br>",$str1);
printf("[%8.8s]<br>",$str2);
?>
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