What is the output statement of php

What is the output statement of php?

The use of PHP output statements is very simple. Not only can it output various types of data, it can also be used for simple debugging during learning and development. There are a series of output statements in PHP, of which common ones include echo, print, print_r(), and var_dump().

php output statements

Common output statements

echo(): can output multiple values ​​at one time, multiple Separate values ​​with commas. echo is a language construct, not a real function, so it cannot be used as part of an expression.

print(): The function print() prints a value (its parameter) and returns true if the string is successfully displayed, otherwise it returns false.

print_r(): Strings and numbers can be simply printed out, while arrays are displayed as a bracketed list of keys and values, starting with Array. But the results of print_r() outputting Boolean values ​​and NULL are meaningless, because they all print "\n". Therefore, using the var_dump() function is more suitable for debugging.

var_dump(): Determine the type and length of a variable, and output the value of the variable. If the variable has a value, the value of the variable is output and the data type is returned. This function displays structural information about one or more expressions, including the expression's type and value. Arrays will expand values ​​recursively, showing their structure through indentation.

There are two basic output methods in PHP: echo and print.

The difference between echo and print:

echo can output one or more strings

print only allows output of one string and returns The value is always 1

Note: echo outputs faster than print. Echo has no return value, while print has a return value of 1.

echo statement

echo is a language structure, which can be used without parentheses or with parentheses: echo or echo().

print statement

print is also a language structure that can use parentheses or not: print or print().

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