Sometimes when coding in PHP language, we will be asked to output one or more strings. What should we do when encountering this situation? At this time we need to use the PHP function echo(). Next, this article will talk to you about the usage of the echo() function in php. Let’s take a look at a specific example of the echo() function.
Definition and usage
The PHP function echo() outputs one or more strings.
Syntax
echo(strings)
Parameter Description
strings Required. One or more strings to send to the output.
Tips and Notes
Note: echo() is not actually a function, but a language construct, so there is no need to use parentheses on it. However, if you expect to pass one or more arguments to echo(), using parentheses will result in a parsing error.
Tip: The echo() function is a little faster than the print() function.
Tip: PHP function echo() can use simplified syntax. As shown in the following example:
<html> <body> php $color = "red"; ?> <p>Roses are =$color?> < SPAN>< span>p> < SPAN>< span>body> < SPAN>< span>html>
1. echo output scalar
php echo 123adb; //输出正确 echo 123abd; //正确 echo "123adb"; //正确 ?>
2. PHP function echo() output variable, constant
php $a="123456"; echo $a; //正确 echo "< span>br>"; echo "$a"; //正确 echo "< span>br>"; echo $a;//不正确 echo "< span>br>"; echo abcdef; //也能正确的显示，但是强烈不建议这么做，因为有很多特殊符号这么做不能正确的显示。 echo "< span>br>"; //echo <abd>; //比如说这样，带了尖括的，就不能用，你可以去了前面的注释试试会不会报错。 echo "< span>br>"; $b=10; echo $b+10; //显示 20 echo "< span>br>"; echo "$b+10"; echo "< span>br>"; echo "结果是："."$b"; //这两种写法的效果是一样的。 echo "< span>br>"; echo "结果是：$b"; //这两种写法的效果是一样的。 ?>
echo "" is different from the PHP function echo(). When double quotes are added, variables and specific symbols will be escaped. When single quotes are added, variables and specific symbols will not be escaped. Symbols are output directly, so using single quotes is faster than using double quotes. If you can do without double quotes, don't use them.
Recommended related articles:
In-depth analysis of the language structure echo in PHP (recommended)
php echo output string function detailed explanation
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