Go 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 string  1 , always.

3. printf function:

int 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:

= "Hunte"$age  =printf$name$age);

4. sprintf function:

string 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:

printfThe call format for the () function is:printf("< formatted string >", < Parameter table >); % D Decimal signed integer% u decimal unsigned integer% F floating point number% s string% C single character%the value of the p pointer%floating-point numbers in e -exponential form%x, % X unsigned integer in hexadecimal notation% o unsigned integer represented in octal%gAutomatic 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    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 16 decimal

Attention:

<br/>: Wrappingin HTML, showing another line, viewing the source file in another line

\ n:the line break in PHP, the performance does not wrap, see the source file for a line

6. printf () : examples

Example 1: various examples

$n= 43951789; $u=-43951789; $c= 65;//ASCII-is ' a '//notice the double percent, this prints A literal '% ' characterprintf("%%b = '%b ' \ n",$n);//binary Representationprintf("%%c = '%c ' \ n",$c);//Print the ASCII character, same as Chr () functionprintf("%%d = '%d ' \ n",$n);//Standard integer representationprintf("%%e = '%e ' \ n",$n);//Scientific notationprintf("%%u = '%u ' \ n",$n);//unsigned integer representation of a positive integerprintf("%%u = '%u ' \ n",$u);//unsigned integer representation of a negative integerprintf("%%f = '%f ' \ n",$n);//floating point representationprintf("%%o = '%o ' \ n",$n);//octal representationprintf("%%s = '%s ' \ n",$n);//string Representationprintf("%%x = '%x ' \ n",$n);//hexadecimal representation (lower-case)printf("%%x = '%x ' \ n",$n);//hexadecimal representation (upper-case) printf("%%+d = '%+d ' \ n",$n);//Sign specifier on a positive integerprintf("%%+d = '%+d ' \ n",$u);//Sign specifier on a negative integerThe printout of this program would is:%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

$s= ' Monkey '; $t= ' Many monkeys '; printf("[%s]\n",$s);//Standard string Outputprintf("[%10s]\n",$s);//right-justification with Spacesprintf("[%-10s]\n",$s);//left-justification with Spacesprintf("[%010s]\n",$s);//zero-padding works on strings tooprintf("[% ' #10s]\n",$s);//Use the custom padding character ' # 'printf("[%10.10s]\n",$t);//Left-justification But with a cutoff of ten charactersThe printout of this program would is:[ monkey] [monkey] [monkey] [0000monkey] [## #monkey][Many Monke]

Example 3:zero-padded integers

$isodate sprintf $year $month $day);

Example 4:formatting currency

$money 1 = 68.75$money 2 = 54.35$money$money 1$money 2  //$formattedsprintf$money//

Example 5: sprintf () : Scientific notation

$number = 362525200echosprintf$number//

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