PHP print_r的函数很好用，可以用来打印数组、对象等的结构与数据，可惜JavaScript并没有原生提供类似的函数。不过我们可以试着自己来实现这个函数，下面提供一些方法与思路。
方法一
function print_r(theObj) {
var retStr = '';
if (typeof theObj == 'object') {
retStr += '<div style="font-family:Tahoma; font-size:7pt;">';
for (var p in theObj) {
if (typeof theObj[p] == 'object') {
retStr += '<div><b>['+p+'] => ' + typeof(theObj) + '</b></div>';
retStr += '<div style="padding-left:25px;">' + print_r(theObj[p]) + '</div>';
} else {
retStr += '<div>['+p+'] => <b>' + theObj[p] + '</b></div>';
}
}
retStr += '</div>';
}
return retStr;
}
方法二
$(document).ready(function(){
$('#btn').click(function(){
var jsonStr = $('#jsonData').val();
var json = eval('('+jsonStr+')');
(function(){
var print_r = function(o, depth) {
var result = '';
depth || (depth=1);
var indent = new Array(4*depth+1).join(' ');
var indentNext = new Array(4*(depth+1)+1).join(' ');
var indentNextTwo = new Array(4*(depth+2)+1).join(' ');
var tmp = '';
var type = typeof o;
switch(type) {
case 'string':
case 'number':
case 'boolean':
case 'undefined':
case 'function':
tmp += indent + indentNext + o + "\n";
break;
case 'object':
default:
for(var key in o) {
tmp += indentNextTwo + '[' + key + '] = ';
tmp += print_r(o[key], (depth+1));
}
}
result += type + "\n";
result += indentNext + '(' + "\n";
result += tmp;
result += indentNext + ')' + "\n";
return result;
};
alert(print_r(json));
}(json));
});
});
方法三
print_r:function(theObj) {
var retStr = '';
if (typeof theObj == 'object'||typeof theObj == 'array') {
retStr += '<div style="font-family:Tahoma; font-size:7pt;">';
for (var p in theObj) {
if (typeof theObj[p] == 'object' || typeof theObj[p] == 'array') {
retStr += '<div><b>['+p+'] => ' + typeof(theObj) + '</b></div>';
retStr += '<div style="padding-left:25px;">' + XFUPLOAD.Tools.print_r(theObj[p]) + '</div>';
} else {
retStr += '<div>['+p+'] => <b>' + theObj[p] + '</b></div>';
}
}
retStr += '</div>';
}
$("body").append(retStr);
}