js格式化json

- 方法一（格式化或压缩JSON）

function format(txt, compress) {
    var indentChar = '    ';
    if (/^\s*$/.test(txt)) {
        console.log('数据为空,无法格式化! ');
        return;
    }
    try {
        var data = eval('(' + txt + ')');
    } catch (e) {
        console.log('数据源语法错误,格式化失败! 错误信息: ' + e.description, 'err');
        return;
    }
    var draw = [],
        last = false,
        This = this,
        line = compress ? '' : '\n',
        nodeCount = 0,
        maxDepth = 0;

    var notify = function (name, value, isLast, indent, formObj) {
        nodeCount++; /*节点计数*/
        for (var i = 0, tab = ''; i < indent; i++)
            tab += indentChar; /* 缩进HTML */
        tab = compress ? '' : tab; /*压缩模式忽略缩进*/
        maxDepth = ++indent; /*缩进递增并记录*/
        if (value && value.constructor == Array) {
            /*处理数组*/
            draw.push(
                tab + (formObj ? '"' + name + '":' : '') + '[' + line
            ); /*缩进'[' 然后换行*/
            for (var i = 0; i < value.length; i++)
                notify(i, value[i], i == value.length - 1, indent, false);
            draw.push(
                tab + ']' + (isLast ? line : ',' + line)
            ); /*缩进']'换行,若非尾元素则添加逗号*/
        } else if (value && typeof value == 'object') {
            /*处理对象*/
            draw.push(
                tab + (formObj ? '"' + name + '":' : '') + '{' + line
            ); /*缩进'{' 然后换行*/
            var len = 0,
                i = 0;
            for (var key in value)
                len++;
            for (var key in value)
                notify(key, value[key], ++i == len, indent, true);
            draw.push(
                tab + '}' + (isLast ? line : ',' + line)
            ); /*缩进'}'换行,若非尾元素则添加逗号*/
        } else {
            if (typeof value == 'string') value = '"' + value + '"';
            draw.push(
                tab +
                (formObj ? '"' + name + '":' : '') +
                value +
                (isLast ? '' : ',') +
                line
            );
        }
    };
    var isLast = true,
        indent = 0;
    notify('', data, isLast, indent, false);
    return draw.join('');
}

• 使用

format(json,true）;表示压缩json字符串。

format(json,false）;表示格式化json字符串

- 方法二（格式化JSON）

var formatJson = function (json, options) {
    var reg = null,
        formatted = '',
        pad = 0,
        PADDING = '    ';
    options = options || {};
    options.newlineAfterColonIfBeforeBraceOrBracket = (options.newlineAfterColonIfBeforeBraceOrBracket === true) ? true : false;
    options.spaceAfterColon = (options.spaceAfterColon === false) ? false : true;
    if (typeof json !== 'string') {
        json = JSON.stringify(json);
    } else {
        json = JSON.parse(json);
        json = JSON.stringify(json);
    }
    reg = /([\{\}])/g;
    json = json.replace(reg, '\r\n$1\r\n');
    reg = /([\[\]])/g;
    json = json.replace(reg, '\r\n$1\r\n');
    reg = /(\,)/g;
    json = json.replace(reg, '$1\r\n');
    reg = /(\r\n\r\n)/g;
    json = json.replace(reg, '\r\n');
    reg = /\r\n\,/g;
    json = json.replace(reg, ',');
    if (!options.newlineAfterColonIfBeforeBraceOrBracket) {
        reg = /\:\r\n\{/g;
        json = json.replace(reg, ':{');
        reg = /\:\r\n\[/g;
        json = json.replace(reg, ':[');
    }
    if (options.spaceAfterColon) {
        reg = /\:/g;
        json = json.replace(reg, ':');
    }
    (json.split('\r\n')).forEach(function (node, index) {
            var i = 0,
                indent = 0,
                padding = '';
            if (node.match(/\{$/) || node.match(/\[$/)) {
                indent = 1;
            } else if (node.match(/\}/) || node.match(/\]/)) {
                if (pad !== 0) {
                    pad -= 1;
                }
            } else {
                indent = 0;
            }
            for (i = 0; i < pad; i++) {
                padding += PADDING;
            }
            if(node == "") {
                formatted += padding + node + '\r\n';
            }
            pad += indent;
        }
    );
    return formatted;
};

• 使用

var jsonObj = {
    "name":"bxd"
}
formatJson(jsonObj); // 格式化json