PHP中echo(),print(),print
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入 echo ,print的区别在于echo 可以输出多个变量值,而print只有一个变量,做为一个字符串输出。 另一点区别在于echo 没有返回值,print有返回值1.print不能输出数组和对象。 print_r可以输出stirng、in
欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入
echo ,print的区别在于echo 可以输出多个变量值,而print只有一个变量,做为一个字符串输出。 另一点区别在于echo 没有返回值,print有返回值1.print不能输出数组和对象。
print_r可以输出stirng、int、float、array、object等,输出array时会用结构表示,print_r输出成功时返回true;
而且print_r可以通过print_r($str,true)来使print_r不输出而返回 print_r处理后的值。
可以理解为:
print 是打印字符串
print_r 则是打印复合类型 如数组 对象等
在PHP中的执行速率从快到慢为:echo(), print(), print_r()
echo是PHP语句, print和print_r是函数,语句没有返回值,函数可以有返回值(即便没有用)
print() 只能打印出简单类型变量的值(如int,string)
print_r() 可以打印出复杂类型变量的值(如数组,对象)
echo 输出一个或者多个字符串
echo -- 输出一个或者多个字符串
Descrīption
void echo ( string arg1 [, string …] ) //返回值为空
echo "你好"," 朋友";
print --输出一个字符串
Descrīption
int print ( string arg )//返回值为整形
print "你好朋友";
可以进行下面操作
$name=print "nihao /n";
$str = 'test print value is $name .';
eval_r("/$print=/"$str/";");
echo $print;
print_r -- 打印关于变量的易于理解的信息。
bool print_r ( mixed expression [, bool return] ) //返回值是布尔型的,参数是mix类型的,可以是字符串,整形,数组,对象类print_r() 显示关于一个变量的易于理解的信息。如果给出的是 string、integer 或 float,将打印变量值本身。如果给出的是 array,将会按照一定格式显示键和元素。object 与数组类似。
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