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print_r

以易于理解的格式打印变量
名称:print_r
分类:变量处理
所属语言:php
一句话介绍:以人类可读的方式打印有关变量的信息。

实例

以更易读的方式打印一些变量的信息:

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token keyword">array</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"red"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"green"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"blue"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token keyword">echo</span> <span class="token string double-quoted-string">"<br>"</span><span class="token punctuation">;</span>

<span class="token variable">$b</span> <span class="token operator">=</span> <span class="token keyword">array</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Peter"</span><span class="token operator">=></span><span class="token string double-quoted-string">"35"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"Ben"</span><span class="token operator">=></span><span class="token string double-quoted-string">"37"</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"Joe"</span><span class="token operator">=></span><span class="token string double-quoted-string">"43"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$b</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

亲自试一试

同类函数
  • 检测变量是否是浮点型  is_float

    is_float

    检测变量是否是浮点型
  • 检测变量是否为 null  is_null

    is_null

    检测变量是否为null
  • 检测变量是否是字符串  is_string

    is_string

    检测变量是否是字符串
  • 获取变量的字符串值  strval

    strval

    获取变量的字符串值
  • 获取变量的布尔值  boolval

    boolval

    获取变量的布尔值
  • 检测变量是否为数字或数字字符串  is_numeric

    is_numeric

    检测变量是否为数字或数字字符串
  • is_float 的别名  is_real

    is_real

    is_float的别名
  • 检查一个变量是否为空  empty

    empty

    检查一个变量是否为空
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