js 格式化字符串

js 格式化字符串

String.prototype.format = function(...args) {
    if (args.length == 1 && typeof args[0] == 'object') {
        let k = '', v = ''
        return this.replace(/{[A-Za-z]+}/g, (it, i) => {
            k = it.slice(1, -1)
            v = args[0][k]
            return typeof v != 'undefined' ? v : '';
        })
    }
    return this.replace(/{(\d+)}/g, (it, i) => {
        return typeof args[i] != 'undefined' ? args[i] : '';
    });
};
console.log("我是{0}，今年{1}了. {2}".format("zhgl", 42, 0))
console.log("我是{name}，今年{age}了.".format({ name: "zhgl", age: 42 }))