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javascript是否有类似“range()”的方法在提供的界限内生成范围?

arrays javascript

609

alex · 技术社区 · 14 年前

在PHP中,您可以……

range(1, 3); // Array(1, 2, 3)
range("A", "C"); // Array("A", "B", "C")

也就是说,有一个函数可以让您通过传递上界和下界来获得数字或字符的范围。

有没有内置到本机的javascript中?如果没有,我将如何实现它?

50 回复 | 直到 6 年前

949

Ben 6 年前

[...Array(5).keys()];
 => [0, 1, 2, 3, 4]

String.fromCharCode(...[...Array('D'.charCodeAt(0) - 'A'.charCodeAt(0) + 1).keys()].map(i => i + 'A'.charCodeAt(0)));
 => "ABCD"

for (const x of Array(5).keys()) {
  console.log(x, String.fromCharCode('A'.charCodeAt(0) + x));
}
 => 0,"A" 1,"B" 2,"C" 3,"D" 4,"E"

function range(size, startAt = 0) {
    return [...Array(size).keys()].map(i => i + startAt);
}

function characterRange(startChar, endChar) {
    return String.fromCharCode(...range(endChar.charCodeAt(0) -
            startChar.charCodeAt(0), startChar.charCodeAt(0)))
}

function range(size:number, startAt:number = 0):ReadonlyArray<number> {
    return [...Array(size).keys()].map(i => i + startAt);
}

function characterRange(startChar:string, endChar:string):ReadonlyArray<string> {
    return String.fromCharCode(...range(endChar.charCodeAt(0) -
            startChar.charCodeAt(0), startChar.charCodeAt(0)))
}

_.range()

_.range(10);
 => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
_.range(1, 11);
 => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
_.range(0, 30, 5);
 => [0, 5, 10, 15, 20, 25]
_.range(0, -10, -1);
 => [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
String.fromCharCode(..._.range('A'.charCodeAt(0), 'D'.charCodeAt(0) + 1));
 => "ABCD"

Array.apply(null, Array(5)).map(function (_, i) {return i;});
 => [0, 1, 2, 3, 4]

console.log([...Array(5).keys()]);

262

dman 7 年前

Array.from() which works in everything these days

Array.from({length: 20}, (x,i) => i);

Array.from(new Array(20), (x,i) => i)

Array.from(Array(20).keys())
// or
[...Array(20).keys()]

Array.from(new Array(20), (x,i) => i + *lowerBound*)

http://www.2ality.com/2014/05/es6-array-methods.html

Kutyel 6 年前

Array(10).fill(1).map((x, y) => x + y)

step

const range = (start, stop, step = 1) =>
  Array(Math.ceil((stop - start) / step)).fill(start).map((x, y) => x + y * step)

Kutyel 6 年前

function range(start, count) {
  return Array.apply(0, Array(count))
    .map((element, index) => index + start);
}

mplungjan Gvidas 8 年前

var range = function(start, end, step) {
    var range = [];
    var typeofStart = typeof start;
    var typeofEnd = typeof end;

    if (step === 0) {
        throw TypeError("Step cannot be zero.");
    }

    if (typeofStart == "undefined" || typeofEnd == "undefined") {
        throw TypeError("Must pass start and end arguments.");
    } else if (typeofStart != typeofEnd) {
        throw TypeError("Start and end arguments must be of same type.");
    }

    typeof step == "undefined" && (step = 1);

    if (end < start) {
        step = -step;
    }

    if (typeofStart == "number") {

        while (step > 0 ? end >= start : end <= start) {
            range.push(start);
            start += step;
        }

    } else if (typeofStart == "string") {

        if (start.length != 1 || end.length != 1) {
            throw TypeError("Only strings with one character are supported.");
        }

        start = start.charCodeAt(0);
        end = end.charCodeAt(0);

        while (step > 0 ? end >= start : end <= start) {
            range.push(String.fromCharCode(start));
            start += step;
        }

    } else {
        throw TypeError("Only string and number types are supported");
    }

    return range;

}

jsFiddle

Array.range

var range = function(start, end, step) {
    var range = [];
    var typeofStart = typeof start;
    var typeofEnd = typeof end;

    if (step === 0) {
        throw TypeError("Step cannot be zero.");
    }

    if (typeofStart == "undefined" || typeofEnd == "undefined") {
        throw TypeError("Must pass start and end arguments.");
    } else if (typeofStart != typeofEnd) {
        throw TypeError("Start and end arguments must be of same type.");
    }

    typeof step == "undefined" && (step = 1);

    if (end < start) {
        step = -step;
    }

    if (typeofStart == "number") {

        while (step > 0 ? end >= start : end <= start) {
            range.push(start);
            start += step;
        }

    } else if (typeofStart == "string") {

        if (start.length != 1 || end.length != 1) {
            throw TypeError("Only strings with one character are supported.");
        }

        start = start.charCodeAt(0);
        end = end.charCodeAt(0);

        while (step > 0 ? end >= start : end <= start) {
            range.push(String.fromCharCode(start));
            start += step;
        }

    } else {
        throw TypeError("Only string and number types are supported");
    }

    return range;

}

console.log(range("A", "Z", 1));
console.log(range("Z", "A", 1));
console.log(range("A", "Z", 3));


console.log(range(0, 25, 1));

console.log(range(0, 25, 5));
console.log(range(20, 5, 5));

Kerem 6 年前

function range(start, stop, step) {
    var a = [start], b = start;
    while (b < stop) {
        a.push(b += step || 1);
    }
    return a;
}

kennebec 14 年前

Array.range= function(a, b, step){
    var A= [];
    if(typeof a== 'number'){
        A[0]= a;
        step= step || 1;
        while(a+step<= b){
            A[A.length]= a+= step;
        }
    }
    else{
        var s= 'abcdefghijklmnopqrstuvwxyz';
        if(a=== a.toUpperCase()){
            b=b.toUpperCase();
            s= s.toUpperCase();
        }
        s= s.substring(s.indexOf(a), s.indexOf(b)+ 1);
        A= s.split('');        
    }
    return A;
}


    Array.range(0,10);
    // [0,1,2,3,4,5,6,7,8,9,10]

    Array.range(-100,100,20);
    // [-100,-80,-60,-40,-20,0,20,40,60,80,100]

    Array.range('A','F');
    // ['A','B','C','D','E','F')

    Array.range('m','r');
    // ['m','n','o','p','q','r']

Alireza 7 年前

range()

function numberRange (start, end) {
  return new Array(end - start).fill().map((d, i) => i + start);
}

numberRange(5, 10); //[5, 6, 7, 8, 9]

function alphabetRange (start, end) {
  return new Array(end.charCodeAt(0) - start.charCodeAt(0)).fill().map((d, i) => String.fromCharCode(i + start.charCodeAt(0)));
}

alphabetRange('c', 'h'); //["c", "d", "e", "f", "g"]

Community CDub 8 年前

function range(start, end, step, offset) {
  
  var len = (Math.abs(end - start) + ((offset || 0) * 2)) / (step || 1) + 1;
  var direction = start < end ? 1 : -1;
  var startingPoint = start - (direction * (offset || 0));
  var stepSize = direction * (step || 1);
  
  return Array(len).fill(0).map(function(_, index) {
    return startingPoint + (stepSize * index);
  });
  
}

console.log('range(1, 5)=> ' + range(1, 5));
console.log('range(5, 1)=> ' + range(5, 1));
console.log('range(5, 5)=> ' + range(5, 5));
console.log('range(-5, 5)=> ' + range(-5, 5));
console.log('range(-10, 5, 5)=> ' + range(-10, 5, 5));
console.log('range(1, 5, 1, 2)=> ' + range(1, 5, 1, 2));

range(5,10) // [5, 6, 7, 8, 9, 10]
range(10,5) // [10, 9, 8, 7, 6, 5]
range(10,2,2) // [10, 8, 6, 4, 2]
range(5,10,0,-1) // [6, 7, 8, 9] not 5,10 themselves
range(5,10,0,1) // [4, 5, 6, 7, 8, 9, 10, 11]
range(5,10,0,-2) // [7, 8]
range(10,0,2,2) // [12, 10, 8, 6, 4, 2, 0, -2]

(step || 1) step 1
(Math.abs(end - start) + ((offset || 0) * 2)) / (step || 1) + 1)
new Array(length).fill(0); check here
[0,0,0,..] Array.map(function() {})
var direction = start < end ? 1 : 0; start end
startingPoint stepSize index

Klesun Gian Marco 9 年前

var range = (l,r) => new Array(r - l).fill().map((_,k) => k + l);

c.P.u1 10 年前

spread operator

var range = (start, end) => [...Array(end - start + 1)].map((_, i) => start + i);

range(10, 15);
[ 10, 11, 12, 13, 14, 15 ]

Mike Dinescu 7 年前

ECMA-262 Standard

yoniLavi qwwqwwq 10 年前

Checkout the jsperf comparison

function range(lowEnd,highEnd){
    var arr = [],
    c = highEnd - lowEnd + 1;
    while ( c-- ) {
        arr[c] = highEnd--
    }
    return arr;
}
range(0,31);

Rick Hitchcock 11 年前

function r(a,b){return a>b?[]:[a].concat(r(++a,b))}

function r(a,b){return (a<b?[a,b].concat(r(++a,--b)):a>b?[]:[a]).sort(function(a,b){return a-b})}

Paolo Moretti 8 年前

lodash Undescore.js range

var range = require('lodash/range')
range(10)
// -> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]

Array.apply(undefined, { length: 10 }).map(Number.call, Number)
// -> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]

generators

function* range(start=0, end=null, step=1) {
  if (end == null) {
    end = start;
    start = 0;
  }

  for (let i=start; i < end; i+=step) {
    yield i;
  }
}

for (let i of range(1, oneZillion)) {
  console.log(i);
}

Sasha Zezulinsky 10 年前

function range(start, end) {
    return Array(end-start).join(0).split(0).map(function(val, id) {return id+start});
}  

range(-4,2);
// [-4,-3,-2,-1,0,1]

range(3,9);
// [3,4,5,6,7,8]

>>> range(-4,2)
[-4, -3, -2, -1, 0, 1]

dietary-wheevil 8 年前

Array.from()

const getRange = (start, stop) => Array.from(
  new Array((stop - start) + 1),
  (_, i) => i + start
);

Hero Qu 8 年前

Paolo Moretti answer with ES6 generators

const RANGE = (a,b) => Array.from((function*(x,y){
  while (x <= y) yield x++;
})(a,b));

console.log(RANGE(3,7));  // [ 3, 4, 5, 6, 7 ]

const RANGE_ITER = (a,b) => (function*(x,y){
  while (x++< y) yield x;
})(a,b);

for (let n of RANGE_ITER(3,7)){
  console.log(n);
}

user642922 11 年前

range

function range(start, end) {
    var total = [];

    if (!end) {
        end = start;
        start = 0;
    }

    for (var i = start; i < end; i += 1) {
        total.push(i);
    }

    return total;
}

console.log(range(10)); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 
console.log(range(0, 10)); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
console.log(range(5, 10)); // [5, 6, 7, 8, 9]

Janus Troelsen 8 年前

Harmony generators supported by all browsers except IE11

var take = function (amount, generator) {
    var a = [];

    try {
        while (amount) {
            a.push(generator.next());
            amount -= 1;
        }
    } catch (e) {}

    return a;
};

var takeAll = function (gen) {
    var a = [],
        x;

    try {
        do {
            x = a.push(gen.next());
        } while (x);
    } catch (e) {}

    return a;
};

var range = (function (d) {
    var unlimited = (typeof d.to === "undefined");

    if (typeof d.from === "undefined") {
        d.from = 0;
    }

    if (typeof d.step === "undefined") {
        if (unlimited) {
            d.step = 1;
        }
    } else {
        if (typeof d.from !== "string") {
            if (d.from < d.to) {
                d.step = 1;
            } else {
                d.step = -1;
            }
        } else {
            if (d.from.charCodeAt(0) < d.to.charCodeAt(0)) {
                d.step = 1;
            } else {
                d.step = -1;
            }
        }
    }

    if (typeof d.from === "string") {
        for (let i = d.from.charCodeAt(0); (d.step > 0) ? (unlimited ? true : i <= d.to.charCodeAt(0)) : (i >= d.to.charCodeAt(0)); i += d.step) {
            yield String.fromCharCode(i);
        }
    } else {
        for (let i = d.from; (d.step > 0) ? (unlimited ? true : i <= d.to) : (i >= d.to); i += d.step) {
            yield i;
        }
    }
});

take

take(10, range( {from: 100, step: 5, to: 120} ) )

[100, 105, 110, 115, 120]

to

take(10, range( {from: 100, step: 5} ) )

[100, 105, 110, 115, 120, 125, 130, 135, 140, 145]

from

takeAll( range( {to: 5} ) )

[0, 1, 2, 3, 4, 5]

takeAll( range( {to: 500, step: 100} ) )

[0, 100, 200, 300, 400, 500]

takeAll( range( {from: 'z', to: 'a'} ) )

["z", "y", "x", "w", "v", "u", "t", "s", "r", "q", "p", "o", "n", "m", "l", "k", "j", "i", "h", "g", "f", "e", "d", "c", "b", "a"]

Evan Carroll 6 年前

`range(start,end,step)`

range()

function * range ( start, end, step = 1 ) {
  let state = start;
  while ( state < end ) {
    yield state;
    state += step;
  }
  return;
};

Array.from()

const generate_array = (start,end,step) =>
  Array.from( range(start,end,step) );

const array1 = generate_array(1,10,2);
const array1 = generate_array(1,7);

for ( const i of range(1, Number.MAX_SAFE_INTEGER, 7) ) {
  console.log(i)
}

Ramda, they have their own R.range Lodash

Bhargav Rao rlgjr 10 年前

lodash _.range(10) https://lodash.com/docs#range

jhaskell 10 年前

function range(start, stop)
{
    var array = [];

    var length = stop - start; 

    for (var i = 0; i <= length; i++) { 
        array[i] = start;
        start++;
    }

    return array;
}

console.log(range(1, 7));  // [1,2,3,4,5,6,7]
console.log(range(5, 10)); // [5,6,7,8,9,10]
console.log(range(-2, 3)); // [-2,-1,0,1,2,3]

John Swindin 7 年前

function range(s, e, str){
  // create generator that handles numbers & strings.
  function *gen(s, e, str){
    while(s <= e){
      yield (!str) ? s : str[s]
      s++
    }
  }
  if (typeof s === 'string' && !str)
    str = 'abcdefghijklmnopqrstuvwxyz'
  const from = (!str) ? s : str.indexOf(s)
  const to = (!str) ? e : str.indexOf(e)
  // use the generator and return.
  return [...gen(from, to, str)]
}

// usage ...
console.log(range('l', 'w'))
//=> [ 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w' ]

console.log(range(7, 12))
//=> [ 7, 8, 9, 10, 11, 12 ]

// first 'o' to first 't' of passed in string.
console.log(range('o', 't', "ssshhhooooouuut!!!!"))
// => [ 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 't' ]

// only lowercase args allowed here, but ...
console.log(range('m', 'v').map(v=>v.toUpperCase()))
//=> [ 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V' ]

// => and decreasing range ...
console.log(range('m', 'v').map(v=>v.toUpperCase()).reverse())

// => ... and with a step
console.log(range('m', 'v')
          .map(v=>v.toUpperCase())
          .reverse()
          .reduce((acc, c, i) => (i % 2) ? acc.concat(c) : acc, []))

// ... etc, etc.

Bob Baxley 9 年前

https://github.com/mbostock/d3/wiki/Arrays#d3_range

d3.range(10)
// returns [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Anona112 8 年前

function range(start, stop, step=1){
  if(!stop){stop=start;start=0;}
  return Array.from(new Array(int((stop-start)/step)), (x,i) => start+ i*step)
}

if(stop<start)step=-Math.abs(step)

range=(b, e, step=1)=>{
  if(!e){e=b;b=0}
  return Array.from(new Array(int((e-b)/step)), (_,i) => b<e? b+i*step : b-i*step)
}

Golo Roden 7 年前

bereich

console.log(...bereich(1, 10));
// => 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

const numbers = Array.from(bereich(1, 10));
// => [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]

for (const number of bereich(1, 10)) {
  // ...
}

min max 1

nha 9 年前

// [begin, end[
const range = (b, e) => Array.apply(null, Array(e - b)).map((_, i) => {return i+b;});

const range = (b, e) => Array.apply(null, Array(Math.abs(e - b))).map((_, i) => {return b < e ? i+b : b-i;});

Michael Plautz 8 年前

Array.prototype.map.call(' '.repeat(1 + upper - lower), (v, i) => i + lower)

Array.prototype.map.call(' '.repeat(1 + upper.codePointAt() - lower.codePointAt()), (v, i) => String.fromCodePoint(i + lower.codePointAt()));

Grant Miller 7 年前

const range = Array.from(Array(size)).map((el, idx) => idx+1).slice(begin, end);