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Copy pathdeepCopy.js
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67 lines (56 loc) · 1.48 KB
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Copy pathdeepCopy.js
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67 lines (56 loc) · 1.48 KB
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var utils = {
// 数据类型检测
toType: val =>
Object.prototype.toString.call(val).slice(8, -1).toLocaleLowerCase(),
isFun(func) {
return typeof func.__proto__ === 'function' && typeof func === 'function';
},
each(itor, cb) {
if (typeof cb !== 'function') return;
if (Array.isArray(itor)) {
itor.forEach(cb);
} else if (typeof itor === 'object' && itor) {
for (var key in itor) {
cb(itor[key], key);
}
}
}
};
var copy = function () {
const { toType, isFun, each } = utils;
var target = arguments[0],
map = arguments[arguments.length - 1],
deep,
clone;
map instanceof Map || (map = new Map());
if (toType(target) === 'boolean') {
deep = target;
target = arguments[1];
}
if (map.has(target)) {
return deep ? null : target;
}
// 处理原始值，例如 number，string，boolean，symbol，bigint，null，undefined
if (
/^number|string|boolean|symbol|bigint$/i.test(toType(target)) ||
target == null
) {
return target;
}
// 内置类对象
if (/^regexp|date$/gim.test(toType(target)))
return new target.constructor(target);
// 处理函数
if (isFun(target)) {
return function () {
return target.apply(this, [].slice.call(arguments));
};
}
clone = Array.isArray(target) ? [] : {};
each(target, function (item, key) {
deep && map.set(item, true);
clone[key] = deep ? copy(deep, item, map) : item;
});
return clone;
};
module.exports = copy;