A simple, recursive stringify implementation

stringify.js

function escape(string){
    var chars = []
    for(var i = 0 ; i < string.length; i++){
        var c = string.charAt(i)
        switch(c){
            case '\n':
                chars.push('\\n')
                break
            case '\t':
                chars.push('\\t')
                break
            case '\'':
                chars.push('\\\'')
                break
            case '"':
                chars.push('\\\"')
                break
            default:
                chars.push(c)
        }
    }
    return chars.join('')
}

function stringify(obj){
    if (obj === null){
        return 'null'
    } else if ((typeof obj == 'number') || (typeof obj == 'boolean')){
        return obj.toString()
    } else if (typeof obj == 'string'){
        return '"' + escape(obj) + '"'
    } else if (Array.isArray(obj)){
        return '[' + obj.map(stringify).join(', ') + ']'
    } else if (typeof obj == 'object'){
        return '{' + Object.keys(obj).map(function(k){return stringify(k) + ': ' + stringify(obj[k])}).join(', ') + '}'
    }
}

function test(){
    console.log(stringify({}))
    console.log(stringify(true))
    console.log(stringify('foo'))
    console.log(stringify('the quick brown fox jumps\n\tover the lazy dog'))
    console.log(stringify([1, 'false', false]))
    console.log(stringify({x: 5}))
}

test()