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# ctype_digit

(PHP 4 >= 4.0.4, PHP 5)

ctype_digit -- Check for numeric character(s)

## 说明

bool ctype_digit ( string text )

Checks if all of the characters in the provided string, text, are numerical.

## 参数

text

  The tested string.

## 返回值

Returns `TRUE` if every character in text is a decimal digit, `FALSE` otherwise.

## 范例

例子 1. A ctype_digit() example

`<?php $strings = array('1820.20', '10002', 'wsl!12'); foreach ($strings as $testcase) { if (ctype_digit($testcase)) { echo "The string $testcase consists of all digits.\n"; } else { echo "The string $testcase does not consist of all digits.\n"; } } ?>`

上例将输出：

    The string 1820.20 does not consists of all digits.
    The string 10002 consists of all digits.
    The string wsl!12 does not consists of all digits.

## 参见

ctype_alnum()
ctype_xdigit()

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