PHP Echo, print, printf, sprintf function differences and use

1. Echo Function:

The output function , which is a command, cannot return a value. Echo can be followed by a number of parameters, separated by semicolons, such as:
echo $myvar 1;
Echo, $myvar, "<b>bold</b>";

2. print Function:

is a function that returns a value that can have only one parameter.

int print (string arg)

Outputs arg . Returns 1 , always.

3. printf function:

int printf (string format [, mixed args [, mixed ...])

Produces output according format to, which are described in the documentation for sprintf () .

Returns the length of the outputted string.

The text is formatted for later output, such as:
$name = "Hunte";
$age = 25;
printf ("My name is%s, age%d", $name, $age);

4. sprintf function:

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

Returns a string produced according to the formatting string format .

Similar to printf, but does not print, but returns formatted text, the rest is the same as printf.

5. The printf () function is explained in detail:

The format for calling the printf () function is:
printf ("< formatted string >", < Parameter table >);

%d decimal signed integer
%u decimal unsigned integer
%f floating Point
%s string
%c single character
%p the value of the pointer
Floating-point numbers in the form of%e indices
%x,%x unsigned integer in hexadecimal notation
%o unsigned integer represented in octal
%g automatic selection of appropriate representations

Description

(1). You can insert a number between "%" and a letter to indicate the maximum field width.

① For example:%3d represents the output of 3-bit integers, not enough 3-bit right-justified.

The ②%9.2f represents a floating-point number with an output field width of 9, where the decimal bit is 2, the integer digit is 6, the decimal point is one, and not enough 9-bit right-aligned.

The ③%8s represents the output of a 8-character string, which is not aligns aligned to 8 characters.

④ if the length of the string or the number of integers exceeds the width of the description, the output is based on its actual length.

⑤ floating point number, if the integer number of bits exceeds the width of the indicated integer digits, the actual integer digits will be output;

⑥ fractional digits exceed the indicated decimal width, the output is rounded by the width of the description.

⑦ If you want to add some 0 before the output value, add a 0 before the field width.

For example,%04d means that when you output a value that is less than 4 bits, it will be preceded by 0 to make its total width 4 bits.

⑧ If you use floating-point numbers to represent the output format of a character or integer, the number after the decimal point represents the maximum width, and the number before the decimal point represents the minimum width.

For example,%6.9s indicates that a string with a length of not less than 6 and not greater than 9 is displayed. If it is greater than 9, the contents of the 9th character will be deleted.

(2). You can add a lowercase letter L between "%" and the letter, indicating that the output is a long form.

① For example:%ld indicates an output long integer

②%LF indicates the output double floating-point number

(3). You can control the output left or right alignment, that is, "%" and the letter by adding a "-" sign to indicate that the output is left-justified, otherwise it is right-justified.

① For example:%-7d indicates output 7-bit integer left justified

②%-10s indicates output 10 characters aligns aligned

(4). Some special provisions of the character

①\n line break
②\f Clear screen and change page
③\r Enter
④\t Tab character
⑤\XHH represents an ASCII code with 16-in notation,
⑥ where HH is 1 to 2 x 16 decimal

6. printf () : examples

Example 1: various examples

<?php<br>$n=  43951789;  $u= -43951789;  $c= 65; // ASCII 65 is ‘A‘   // notice the double %%, this prints a literal ‘%‘ character  printf("%%b = ‘%b‘\n", $n); // binary representation  printf("%%c = ‘%c‘\n", $c); // print the ascii character, same as chr() function  printf("%%d = ‘%d‘\n", $n); // standard integer representation  printf("%%e = ‘%e‘\n", $n); // scientific notation  printf("%%u = ‘%u‘\n", $n); // unsigned integer representation of a positive integer  printf("%%u = ‘%u‘\n", $u); // unsigned integer representation of a negative integer  printf("%%f = ‘%f‘\n", $n); // floating point representation  printf("%%o = ‘%o‘\n", $n); // octal representation  printf("%%s = ‘%s‘\n", $n); // string representation  printf("%%x = ‘%x‘\n", $n); // hexadecimal representation (lower-case)  printf("%%X = ‘%X‘\n", $n); // hexadecimal representation (upper-case)  printf("%%+d = ‘%+d‘\n", $n); // sign specifier on a positive integer  printf("%%+d = ‘%+d‘\n", $u); // sign specifier on a negative integer  ?>   The printout of this program would be:   %b = ‘10100111101010011010101101‘%c = ‘A‘%d = ‘43951789‘%e = ‘4.39518e+7‘%u = ‘43951789‘%u = ‘4251015507‘%f = ‘43951789.000000‘%o = ‘247523255‘%s = ‘43951789‘%x = ‘29ea6ad‘ %X = ‘29EA6AD‘%+d = ‘+43951789‘%+d = ‘-43951789‘

Example 2: string Specifiers

<?php$s= ‘monkey‘;  $t= ‘many monkeys‘;     printf("[%s]\n",      $s); // standard string output  printf("[%10s]\n",    $s); // right-justification with spaces  printf("[%-10s]\n",   $s); // left-justification with spaces  printf("[%010s]\n",   $s); // zero-padding works on strings too  printf("[%‘#10s]\n",  $s); // use the custom padding character ‘#‘  printf("[%10.10s]\n", $t); // left-justification but with a cutoff of 10 characters  ?>       The printout of this program would be:   [monkey]  [    monkey]  [monkey    ]  [0000monkey]  [####monkey]  [many monke]

Example 3:zero-padded integers

<?php  $isodate= sprintf("%04d-%02d-%02d", $year, $month, $day);  ?>

Example 4:formatting currency

<?php  $money 1  = 68.75;  $money 2  = 54.35;  $money  = $money 1  + $money 2 ;  //echo $money would output "123.1";  $formatted  = sprintf ( "%01.2f" $money ;  //echo $formatted would output "123.10"   ?>

Example 5: sprintf () : Scientific notation

<?php  $number= 362525200;  echosprintf("%.3e", $number); // outputs 3.63e+8  ?>

PHP Echo, print, printf, sprintf function differences and use