蛇形变量名与驼峰变量名的相互转换

snake_and_camel_convert.php

<?php
// 驼峰命名法转蛇形命名法
function camel2snake ($camel) {
    if (false !== strpos($camel, '_')) {
        return $camel;
    }
    
    $capitalLetters = range('A', 'Z');
    for ($i=1; $i < strlen($camel) - 1; $i++) {
        if (in_array($camel[$i], $capitalLetters)) {
            $camel = str_replace($camel[$i], '_' . strtolower($camel[$i]), $camel);
        }
    }
    
    return $camel;
}

// 蛇形命名法转驼峰命名法
function snake2camel ($snake, $lowerCamelCase = false) {
    // 非下划线变量返回原值
    if (false === strpos($snake, '_')) {
        return $snake;
    }

    $snakeTitle = ucwords($snake, '_');
    $upperCamelCase = str_replace('_', '', $snakeTitle);

    return $lowerCamelCase ? lcfirst($upperCamelCase) : $upperCamelCase;
}