我正在寻找一个与C/PHP printf()或C#/Java程序员String.Format()(IFormatProvider for.NET)相当的JavaScript。

目前,我的基本要求是数字的千位分隔符格式,但处理大量组合(包括日期)的格式会很好。

我意识到Microsoft的Ajax库提供了String.Format()的一个版本,但我们不希望该框架的全部开销。


当前回答

我将添加我自己的发现,这些发现是我问过之后发现的:

number_format(用于千位分隔符/货币格式)sprintf(作者同上)

遗憾的是,sprintf似乎不能像.NET的字符串格式那样处理千位分隔符格式。

其他回答

如果需要printf,请使用printf

看起来90%的评论从未使用过比%d更复杂的printf格式。例如,我想知道他们是如何输出货币价值的?

bobjs可以做到这一点:

var sFormat = "My name is {0} and I am {1} years old."; 
var result = bob.string.formatString(sFormat, "Bob", 29); 
console.log(result); 
//output: 
//========== 
// My name is Bob and I am 29 years old. 
/**
 * Format string by replacing placeholders with value from element with
 * corresponsing index in `replacementArray`.
 * Replaces are made simultaneously, so that replacement values like
 * '{1}' will not mess up the function.
 *
 * Example 1:
 * ('{2} {1} {0}', ['three', 'two' ,'one']) -> 'one two three'
 *
 * Example 2:
 * ('{0}{1}', ['{1}', '{0}']) -> '{1}{0}'
 */
function stringFormat(formatString, replacementArray) {
    return formatString.replace(
        /\{(\d+)\}/g, // Matches placeholders, e.g. '{1}'
        function formatStringReplacer(match, placeholderIndex) {
            // Convert String to Number
            placeholderIndex = Number(placeholderIndex);

            // Make sure that index is within replacement array bounds
            if (placeholderIndex < 0 ||
                placeholderIndex > replacementArray.length - 1
            ) {
                return placeholderIndex;
            }

            // Replace placeholder with value from replacement array
            return replacementArray[placeholderIndex];
        }
    );
}
String.prototype.repeat = function(n) { 
    return new Array(++n).join(this); 
};

String.prototype.pad = function(requiredLength, paddingStr, paddingType) {    
    var n = requiredLength - this.length; 

    if (n) {
        paddingType = paddingType ? paddingType.toLowerCase() : '';
        paddingStr = paddingStr || ' ';
        paddingStr = paddingStr.repeat( Math.ceil(n / paddingStr.length) ).substr(0, n);

        if (paddingType == 'both') {
            n /= 2;
            return paddingStr.substr( 0, Math.ceil(n) ) + this + paddingStr.substr( 0, Math.floor(n) );
        }   

        if (paddingType == 'left') {
            return paddingStr + this;
        }

        return this + paddingStr;
    } 

    return this; 
}; 

// синтаксис аналогичен printf
// 'Привет, %s!'.format('мир') -> "Привет, мир!"
// '%.1s.%.1s. %s'.format('Иван', 'Иванович', 'Иванов') -> "И.И. Иванов"
String.prototype.format = function() {
    var i = 0, 
        params = arguments;

    return this.replace(/%(?:%|(?:(|[+-]+)(|0|'.+?)([1-9]\d*)?(?:\.([1-9]\d*))?)?(s|d|f))/g, function(match, sign, padding, width, precision, type) {
        if (match == '%%') { 
            return '%'; 
        }

        var v = params[i++];

        if (type == 'd') { 
            v = Math.round(v); 
        }
        else if (type == 'f') {
            v = v.toFixed(precision ? precision : 6);
        }

        if (/\+/.test(sign) && v > 0) {
            v = '+' + v;
        }

        v += '';

        if (type != 'f' && precision) {
            v = v.substr(0, precision);
        }

        if (width) {
            v = v.pad(width, padding == '' ? ' ' : padding[0] == "'" ? padding.substr(1) : padding, /-/.test(sign) ? 'right' : 'left'); 
        }

        return v;
    });
};

// this.name = 'Вася';
// console.log( 'Привет, ${name}!'.template(this) );
// "Привет, Вася!"
String.prototype.template = function(context) {
    return this.replace(/\$\{(.*?)\}/g, function(match, name) {
        return context[name];
    });
};

对于Node.js用户,util.format具有类似printf的功能:

util.format("%s world", "Hello")